Book Series

The Old Sarum Witch series by K.E. O'Connor features three witchy mystery novels published in 2017: Witch Kissed, Witch Rose, and Witch Guy.

Old Stories is a three-book picture book series by N.D. Wilson that retells biblical narratives for young children with vivid illustrations by Peter Bentley.

Old Timey Holiday Kitchen is a multi-author western romance series where each story centers on a traditional recipe and a holiday romance on the frontier.

Old Timey Holiday Kitchen is a western romance series by Janice Cole Hopkins combining frontier romance with traditional recipes. The 42 books were published between 2021 and 2025.

The complete reading order for the Old Timey Holiday Kitchen series by Elissa Strati, 42 Western romance novels that pair holiday recipes with love stories in the Old West.

A list of short stories and novellas by Olen Steinhauer, featuring standalone spy fiction and literary short works.

A list of standalone novels by Olen Steinhauer, including the spy thrillers The Cairo Affair and All the Old Knives.

The Oligarchs series by B.B. Hamel features dark romance with wealthy, ruthless Russian power brokers.

A Romantic Hero is a 1967 short story collection by Olivia Manning, her only published gathering of short fiction.

The Olive series by Carol Drinkwater is a nine-book series running from 2001 to 2020, starting with The Olive Farm.

Complete Olive Kitteridge series by Elizabeth Strout in order. Both books in the Pulitzer Prize-winning series, from Olive Kitteridge to Olive, Again.

Oliver K. Langmead's standalone novels include 6 works of speculative fiction published between 2015 and 2025, blending poetry, mythology, and science fiction.

The Oliver Nocturne series by Kevin Emerson follows a young vampire navigating the supernatural world. See all six books in reading order.

Oliver North's non-fiction works include five titles published between 1987 and 2022.

Oliver North's standalone novels span 2014 to 2019, featuring two independent stories.

The Olivia Cruz series by Melinda Leigh follows a true crime writer drawn into real-life criminal investigations, beginning with You Can Tell Me in 2026.

The Olivia Curtis novels by Rosamond Lehmann follow a young woman from her first ball to a complicated love affair, published in 1932 and 1936.

Olivia Davis Paranormal Mysteries is an early series by Tonya Kappes blending paranormal elements with romance and mystery.

A complete list of Olivia Hayle's standalone romance novels in order, from Look But Don't Touch (2019) to Between the Lines (2024).

Olivia Manning contributed short fiction to several anthologies between 1969 and 1979, including entries in the Winter's Tales and Penguin Modern Stories series.

Extraordinary Cats is a 1967 non-fiction book by Olivia Manning about remarkable cats throughout history and literature.

Olivia Manning's standalone novels span from 1937 to 1974 and include her early fiction, a historical narrative about the rescue of Emin Pasha, and several novels set in the Middle East and Britain.

Olivia Miles' standalone novels are self-contained contemporary romances that showcase her range beyond her popular series work.

Olivia Newport Anthologies includes her contribution to A Plain and Sweet Christmas Romance Collection (2016).

Olivia Newport Collections includes Colors of Christmas (2017), a holiday-themed collection of stories.

Olivia Newport's standalone novel Hidden Falls (2017) is a complete mystery set in a small town.

The Olivia Newton series by Preston W. Child is a ten-book adventure thriller series following a female protagonist through treasure-hunting mysteries.

The Olivia Penn Mysteries by Kathleen Bailey follow a small-town sleuth through atmospheric cozy mysteries.

Anthology contributions by Olivia Waite, including Best Women's Erotica of the Year, Volume 6.

Olivia Waite short stories and novellas in order, including The Best Worst Holiday Party Ever and Hen Fever.

All standalone novels by Olivia Waite in order, including Generous Fire, Hearts and Harbingers, A Thief in the Nude, and more.

Olivie Blake anthology contributions, including The Secret Romantic's Book of Magic.

Olivie Blake short fiction, including the novella La Petite Mort.

All Olivie Blake standalone novels in reading order, from Masters of Death to Girl Dinner.

The Ollie Stratford Mystery series by N.C. Lewis features seven Texas-set mysteries published between 2017 and 2018.

The Olympus Bound trilogy by Jordanna Max Brodsky follows ancient Greek gods living in modern Manhattan as they face new threats to their existence.

The Olympus Mountain Man Romance series by Autumn Summers features six romance novels with rugged heroes. See all books in order.

The Olympus Pride series follows members of a cat shifter pride as they find their mates, with the same humor and heat that defines Suzanne Wright's paranormal romance.

The Olympus Project series by Sydney Addae consists of The Leviticus Club, published in 2018.

A complete list of Omar Robert Hamilton's standalone novels, including his award-winning debut The City Always Wins, set during the 2011 Egyptian revolution.

The Omega Force series by Susannah Sandlin — a standalone romantic suspense novel.

The Omega Morales series by Laekan Zea Kemp is a middle grade fantasy adventure drawing on Mexican folklore and featuring a young Latina protagonist.

Omega Stream is a paranormal romance series by Helen Scott featuring omegaverse dynamics in a modern setting across three books.

The Omega Sub series by David Robbins features four submarine-based military thrillers published between 1991 and 1992.

The Omega Taskforce series by G.J. Ogden in reading order. Six military sci-fi novels published in 2021.

The Omega Team Universe is a multi-author romantic suspense series with 43 books published between 2014 and 2020, organized by Sable Hunter.

The Omega Team Universe is a multi-author military romantic suspense franchise featuring special operations veterans, with Tina Donahue as a major contributing author.

The Omega Team Universe is a multi-author romantic suspense series with 41 books featuring elite military operatives, published between 2014 and 2020.

The complete reading order for the Omega University series by J.L. Wilder, a paranormal shifter romance series set at a university for wolf shifters.

The Omega War series is a twelve-book military science fiction saga featuring interstellar conflict, published entirely between 2018 and 2019.

The Omega War series features 12 military sci-fi novels with contributions by Kevin Ikenberry, published in 2018 and 2019.

The Omen of Ice series by Jus Accardo is a two-book series running from 2023 to 2024, starting with Omen of Ice.

Omirabad Sheikhs series by Leslie North follows three royal brothers in this contemporary sheikh romance trilogy set in a fictional Middle Eastern kingdom.

The Henry Kisor Omnibus collects Steve Martinez mysteries in the single volume Porcupine County.

The complete On Dublin Street series by Samantha Young in reading order, a twelve-book contemporary romance series set in Edinburgh, Scotland.

The On Dublin Street Collections in order, featuring bonus material and collected novellas from Samantha Young's Edinburgh-set contemporary romance series.

The On My Knees series by Ella James features contemporary romance novels with themes of devotion, worship, and intense physical and emotional connection.

Complete list of On My Own books in order by Carrie Ann Ryan. A five-book contemporary romance series published from 2020 to 2021.

The On the Bones of Gods series by K. Eason in order, a fantasy trilogy starting with Enemy.

On the Court is a sports romance series by Micalea Smeltzer, beginning with Double Fault in 2026.

The On the Hunt for Love series by Ellie Hall is a two-book romance featuring classic fairy-tale-inspired tropes, including a grumpy hero and a Beauty and the Beast retelling.

The On the Otherside series by Denise Grover Swank in order. Complete reading guide for all 5 books starting with Here (2011).

On The Prowl is a three-book romance series by Kasey Michaels spanning from 1991 to 2001 with stories of love on the hunt.

The On the Right Path series by Michelle Lindo-Rice is an inspirational fiction duology starting with Walk a Straight Line (2013).

The On the Road to Love series by Verlene Landon is a three-book contemporary romance series published in 2019 and 2020, featuring road-trip and travel-themed love stories.

The On the Rocks series by Shaw Hart is a six-book series running from 2021 to 2022, starting with Whiskey Dreams.

The On the Run series by Kimberly Dean follows fugitives and the hunters chasing them, with danger and attraction building at every turn.

On the Verge by Zoraida Córdova is a three-book contemporary romance series starting with Luck on the Line in 2014.

The Once a SEAL, Always a SEAL series by Holly Rayner features seven military romances with former Navy SEALs finding love.

The Once a Wallflower series by Maggi Andersen follows shy Regency heroines who step out of the shadows and into love.

The Once Over series by Shonda Czeschin Fischer is a four-book series running from 2021 to 2021, starting with Strawberry Summer.

The complete reading order for the Once Upon series by Nora Roberts, featuring the novella Dream Loverla, a fairy-tale-inspired contemporary romance.

The Once Upon a Con series by Ashley Poston is a YA romance series set in fandom and convention culture, starting with Geekerella (2017).

The Once Upon a Crime series by Nolon King is a three-book crime thriller trilogy published in 2022.

Once Upon a Crime Family is a two-book YA thriller duology by Tiffany Schmidt, following a girl raised in a powerful crime organization who must navigate loyalty, danger, and her own conscience.

Once Upon a Dickens Christmas is a three-book holiday romance series by Michelle Griep inspired by the world and themes of Charles Dickens.

Once Upon A Dukedom is a three-book Regency romance series by Rachel Hawthorne (Lorraine Heath) reimagining the fairy tale romance through the lens of dukes and the women they pursue.

The reading order for Melissa McClone's Once Upon a Kiss series, thirteen fairy tale-inspired romance novels.

Books from the Once Upon a Kiss multi-author Harlequin romance series.

Once Upon A New York Minute by Sherry Ficklin is a contemporary romance published in two parts in 2019.

The Once Upon a Prince series by Kate Stradling reimagines 12 classic fairy tales from the princes' perspectives in a rapid-fire collection of romantic fantasy retellings all published in 2023.

Once Upon a Regency by Jessilyn Stewart Peaslee is a five-book series of clean Regency romances, each retelling a different classic fairy tale.

A four-book rock star romance series by Michelle Mankin with fairy tale-inspired love stories set in the music world.

Complete reading order for the Once Upon a Rogue series by Julie Johnstone, a four-book Regency romance series.

Once Upon a Scandal by Liana De la Rosa is a Regency historical romance series of four books featuring scandalous lords and the heroines who match them.

The Once Upon a Shifter series by Shaw Hart is a four-book series running from 2023 to 2023, starting with Claiming Beauty.

The Once Upon a Summer series by Lisa T Bergren is a contemporary romance series set in scenic summer locations, published between 1994 and 2020.

Once Upon a Temptation by Lynne Graham features eight fairy-tale-inspired romance novels published in 2020, retelling classic stories with billionaire heroes.

Once Upon a Temptation is a seven-book Harlequin romance series retelling fairy tales with modern billionaire heroes, published in 2020.

The Once Upon a Time in Texas series by Carly Bloom is a four-book contemporary cowboy romance series set in the fictional small town of Big Verde, Texas.

The Once Upon A Time in Texas series by Karen Witemeyer consists of To Love a Beast, published in 2025.

Once Upon a Time in the West is a western romance series by Lori Handeland that retells classic fairy tales in the American frontier setting.

The Once Upon A Time series by Kay Hooper is a nine-book romance collection inspired by fairy tales, published between 1989 and 2001.

Complete list of all Once Upon a Villain books in order by Bianca Cole. Full reading order for this dark fairy tale retelling romance series.

Once Upon a Wedding is a nine-book contemporary romance series by Mona Shroff set around Indian American wedding celebrations, published from 2001 to 2025.

The Once Upon Another Time series by James Riley is a two-book series running from 2022 to 2022, starting with Once Upon Another Time.

The One is a seven-part serialized story by Jess Walter, published as individual episodes in 2019.

One Christmas Night In is a two-book Harlequin romance series by Rita Bradshaw featuring Christmas-themed love stories, published in 2011.

The One Day With You series by Shari Low in reading order, a two-book contemporary fiction duology.

One Fairy Tale Wedding by Noelle Adams is a three-book romance series published in 2018, featuring stories set around a fairy tale-themed wedding.

The One I Want series by Ellie Masters is a contemporary romance series about finding unexpected love, starting with Brent & Brie (2019).

The One Love series by Lauren Blakely is a six-book series running from 2016 to 2020, starting with The Only One.

The One More Chance series by Hayden Hall is a three-book MM second-chance romance published between 2020 and 2021, beginning with One More Shot.

One Night by Noelle Adams is a thirteen-book romance series built around one-night encounters that lead to lasting love, starting in 2012.

The One Night series by Dana Isaly is a six-book dark romance series beginning with Games We Play (2021).

The One Night series by J.S. Cooper collects eight interconnected contemporary romances about impulsive encounters that lead to unexpected relationships.

The One Night at a Wedding series by Mira Lyn Kelly is a two-book series running from 2010 to 2010, starting with Champagne with a Celebrity.

The One Night Stand series by J.S. Cooper explores what happens after impulsive nights together, with nine books following different couples from that first encounter to falling in love.

The reading order for Melissa McClone's One Night to Forever series, four romances about brief encounters that lead to lasting love.

One Night With Consequences is a multi-author Harlequin romance series featuring romances that begin with a single night and lead to unexpected pregnancies. Over 55 books published between 2013 and 2020.

The One Night with You series by Mia Brody is a three-book series running from 2021 to 2021, starting with Mine Tonight.

The One of Us series by Karen M. McManus is a YA thriller trilogy set at Bayview High, starting with One of Us Is Lying.

The One Perfect series by Paige Toon is a pair of linked stories set around Christmas and summer, both published in 2012.

The One Scorching Summer series by Lori Wilde is a steamy contemporary romance trilogy set during a hot Texas summer.

The One Time Only series by Lauren Blakely is a five-book series running from 2020 to 2020, starting with Maybe This Time.

The One True Mate series by Lisa Ladew is an 11-book paranormal shifter romance published between 2016 and 2026.

The One True Mate Companion series by Lisa Ladew is an 11-book companion collection to the One True Mate shifter romance series.

The The One Universe series by John Marrs is a five-book series running from 2016 to 2024, starting with The One.

The One Week in Love series by Julia Kelly is a trio of contemporary romance anthologies set in Wyoming, Hawaii, and during the holiday season, published between 2014 and 2015.

All 3 One Week In Love books in order by Audra North. Complete reading order from One Week in Wyoming to One Week in December.

The One Weekend series by Alexandra Silva features romances that unfold during a single, intense weekend.

The One-Eyed Jacks series by Cindy Gerard is a romantic suspense series about veterans dealing with danger and romance after leaving military service.

One-on-One series reading order by Jamie Wesley, a contemporary sports romance trilogy with love stories set in the world of professional athletics.

Complete reading order for the Only series by Lucy Darling, a 4-book romance series published between 2020 and 2022.

The Only series by Cristin Harber is a collection of contemporary romances about love, family, and second chances.

The Only series by Theresa Hodge is a 2025 romance trilogy following a couple through three stages of their relationship.

The Only series by Elizabeth Lowell features seven historical western romance novels published between 1991 and 1996.

Only For Love is a six-book Regency romance series by Rose Pearson published in 2023, featuring gentlemen and ladies of the ton in unexpected romantic situations.

The Only in Gooding series by Cathy Marie Hake features five Christian historical romance novels set in the fictional town of Gooding, published 2007-2010.

The Only Love series by Garrett Leigh features two connected MM romances about opening yourself to love after loss.

Only Magic in the Building is a ten-book whimsical romance series by Jenny Proctor, published in 2025.

The Only Magic in the Building series by Courtney Walsh is a whimsical Christian romance series set in an enchanted apartment building where magical happenings push the residents toward love.

Only Magic in the Building is a multi-author romance series set in a magical apartment building where love and enchantment collide across ten whimsical entries.

The Only One series by Kennedy Fox features three standalone-connected romance novels published in 2022 about finding the one person you cannot let go of.

The Only Us Billionaire series by Ellie Hall is an eight-book clean billionaire romance that started in 2018, following wealthy heroes and the women who see past the money.

Onslaught novel series by Peter David in reading order, adapting the major Marvel Comics crossover.

A list of standalone novels by Onyi Nwabineli, including Someday, Maybe and Allow Me to Introduce Myself.

The Onyx Assassins is an eight-book paranormal romance series by Samantha Whiskey featuring a 'Crimson' naming pattern, published from 2020 to 2024.

The Onyx Sector Adventure series by Craig A. Hart features seven spy-themed adventure novels with punning titles, published rapidly in 2025 and 2026.

The Oops! series by Holly Rayner features five romances where unexpected situations lead to love, from surprise pregnancies to accidental marriages.

The OP MC is a 20-book harem fantasy series by Logan Jacobs featuring an overpowered main character, subtitled 'God of Winning' in later volumes, published from 2020 to 2022.

The Opal Cowan series by Maria V. Snyder follows a young glass magician caught between two nations in the world of Ixia and Sitia.

The Opar duology by Philip Jose Farmer is set in the lost city of Opar from the Tarzan universe, thousands of years before Tarzan's time.

Open Door 6 is a series of short, accessible novels published in 2008 as part of Ireland's Open Door literacy initiative.

The Open Door 6 series features seven short books published in 2008, designed as accessible reads for adult literacy learners in Ireland.

Open Door 6 is a collection of short, accessible novels published as part of the Open Door literacy series, including contributions by Kate Thompson.

The Open Tab series by Nancy Ann Healy (writing as J.A. Armstrong) is a five-book lesbian romance set in the bar and nightlife world.

Operation Cowboy books in order by Em Petrova. Complete reading order for this western romance duology.

Operation Cupid is a paranormal romance series by Mila Young blending mythology with romantic comedy.

The Operation Erotic series by Cynthia Sax is a five-book erotic romance series starting with Mission Menage (2011).

Operation Family is an eight-book military romance series by Laura Marie Altom about Navy SEALs building families, published between 2003 and 2014 under the Harlequin American Romance line.

The reading order for Mark Hayden's Operation Jigsaw trilogy, a thriller series that introduces the character who later stars in The King's Watch.

Operation Save the Teacher is a three-book middle grade series by Meg Wolitzer about children working together to help their teacher.

Operation Star Hawks by Deborah Chester is a six-book space opera series published from 1990 to 1992, following military science fiction adventures.

The Operation Zulu Redemption series by Ronie Kendig is a three-part military romantic suspense about a covert operation and its aftermath.

Operation: Harvest is a three-book thriller series by Justin Bell published in 2020.

Complete list of Operation: Midnight books in order by Linda Castillo. A five-book romantic suspense series published by Harlequin Intrigue from 2005 to 2007.

Operations by Jonathan Anders is a spy action series by Christopher Nicole featuring Cold War military operations.

Ophelia by Amy Cross is a two-book horror series published in 2014, following a character into a dead city full of dark secrets.

Ophelia Bell's anthology contributions, including Summer Sizzle, Monsters After Dark, Claws and Paws, and Monsters Before Men.

Ophelia Bell's short stories and novellas, including The Coven's Captive (2021).

Opposites Attract books in order by Erin Nicholas. Complete reading order for the Opposites Attract series with publication dates.

The Opposites Collide series by Kathy Coopmans features three contemporary romances about mismatched couples who discover unexpected connections.

The OPSIG Team Black series follows a covert government operations unit through four high-stakes thrillers by Alan Jacobson, beginning with The Hunted in 2001.

Oracles of Delphi Keep is a three-book middle-grade fantasy series by Victoria Laurie about orphans with mystical abilities connected to ancient prophecies.

Orbit Science Fiction Yearbooks is a three-volume science fiction anthology series published between 1988 and 1990, collecting the year's notable science fiction stories.

The Orbitsville trilogy by Bob Shaw explores humanity's discovery and colonization of a vast Dyson sphere surrounding a distant star.

The Orbs series by Anthony J. Melchiorri is a post-apocalyptic alien invasion saga about scientists trapped underground while the surface world is destroyed.

The Orca Currents series features 40 books by Gail Anderson-Dargatz for middle school readers. See all titles in order.

The complete reading order for the Orca Echoes series, a large multi-author collection of early chapter books for beginning readers.

The Orca Echoes series offers short, illustrated chapter books for early readers ages 7-9, featuring adventures, animals, and everyday kid problems.

The complete reading order for the Orca Limelights series, a multi-author collection of performing arts fiction for young readers.

The Orca Limelights series features short novels about teens pursuing their passions in the performing arts, from dance and music to theater and film.

The complete Orca Limelights series in reading order, a multi-author publisher series of 24 YA novels about young people in the performing arts, published from 2013 to 2018.

The complete reading order for the Orca Soundings series, a large multi-author collection of high-interest, low-reading-level novels for teen readers.

The Orca Soundings series features short, high-interest young adult novels from dozens of Canadian authors, covering topics from crime and addiction to identity and survival.

The complete reading order for the Orca Sports series, a multi-author collection of sports fiction for young readers.

OrcFire is a nine-book orc romance series by Alana Khan following the Embers community of orcs, blending fantasy romance with seasonal holiday themes.

The complete reading order for London James's The Orchard Brides series, nine romances set around a family orchard, including a companion cookbook.

The Orchard Inn series by Heather McGovern in order, starting with Something Blue, a contemporary romance series.

Orchid Island is a single-book island romance by JoAnn Ross, published in 2015 as part of her return to self-published contemporary romance.

The Orchid Valley series by Lexi Ryan is a five-book small town romance set in a tight-knit community. See all books in order.

Orcs Unbound is a 12-book orc romance series by Alana Khan featuring powerful orc heroes and the human women they claim, protect, and cherish.

The The Order series by Edward W. Robertson is a six-book series running from 2013 to 2024, starting with Rago.

The Order of Merlin is an urban fantasy series by Thomas K. Carpenter set in the Hundred Halls universe, following agents who enforce magical law and investigate threats that ordinary hall students never see.

Order of Prometheus is a two-book urban fantasy series by Katerina Martinez following a secret magical organization and the supernatural conflicts it navigates.

The Order of Scion series by Toby Neighbors is a science fiction saga about characters with gravity-manipulating powers.

The Order Of Solace series by Megan Hart is a five-book series running from 2009 to 2019, starting with Pleasure and Purpose.

The Order of the Cronus series by M.E. Clayton is a five-book series running from 2022 to 2022, starting with Typhon.

The Order of the Dragon series by Tina Glasneck is a paranormal romance trilogy featuring vampires and supernatural warfare, beginning with Zero Hour in 2019.

The Order of the Dragon Wolf's Den series by Tina Glasneck is a seven-book paranormal romance spinoff featuring vampires and wolf shifters.

The Order of the Fallen series by Jenna Wolfhart is a paranormal romance trilogy starting with Ruinous, featuring fallen angels and forbidden attraction.

The Order of the Fire series by P.E. Padilla is an epic fantasy trilogy about warriors sworn to protect the world of Gythe from supernatural threats.

The Order of the Sanguines series, co-written by James Rollins and Rebecca Cantrell, blends religious history with supernatural thriller elements in a battle between ancient forces.

The Order of the Seven Stars series by Luanne G. Smith is a historical fantasy duology set during World War I, blending wartime drama with magic.

The Order of the Unseen series by Molly Doyle is a dark paranormal romance featuring masked figures, psychological tension, and a storyline that spans four books.

The Ordinary Farm Adventures series by Tad Williams is a middle-grade fantasy about two kids who discover their great-uncle's farm is home to dragons and other mythical creatures.

The Ordinary Women of the Bible series features 20 biblical fiction novellas published from 2019 to 2024, each about a lesser-known woman from Scripture.

The Oregon Coast / Seavy Village series by Kristine Kathryn Rusch collects mysteries and supernatural stories set along the Oregon coast.

The Oregon Files series follows the crew of a high-tech spy ship on covert missions worldwide, created by Clive Cussler and continued by multiple co-authors including Mike Maden.