O
- Obsessed - Susan Andersen, 1993 (Zebra)
- Obsession - Multiple Authors
- Ocean Between Us, The - Susan Wiggs, 2004 (Mira)
- Odd Man Out - Multiple Authors
- Odd Mom Out - Jane Porter, 2007 (Grand Central Publishing)
- Of Cats And Kings - Beverly Sommers, 1987 (Harlequin American Romance)
- Of Water and Dragons - Kelley Heckart, 2005
- Officer And A Gentleman, An - Rachel Lee, 1990 (Silhouette Intimate Moments)
- Officer And A Gentle Woman, An - Doreen Owens Malek , 1999 (Silhouette Intimate Moments)
- Officer And A Hero, An - Elizabeth Ashtree, 1999 (Harlequin Superromance)
- Officer And A Princess, An - Carla Cassidy, 2001 (Silhouette Romance)
- Offer He Can't Refuse, An - Christie Ridgway, 2005 (Avon)
- Official Duty - Doreen Roberts, 2004 (Harlequin Intrigue)
- Oh Baby! - Lauryn Chandler, 1994
- Oklahoma Man - Delayne Camp, 1991 (Harlequin Temptation)
- Old Dreams, New Dreams - Jacqueline Diamond, 1991 (Harlequin American Romance)
- On A Wicked Dawn, Stephanie Laurens, 2002 (Avon)
- On A Wild Night, Stephanie Laurens, 2002 (Avon)
- On Eagle's Wings - Rebecca Goings, 2005
- On Executive Orders - Rianna Craig, 1986 (Harlequin Intrigue)
- On The Edge - Multiple Authors
- On The List - Patricia Rosemoor, 2004 (Harlequin Intrigue)
- On The Naughty List - Jaycee Clark, Ellen Fisher, and Angelica Hart, 2005 (New Concepts Publishing)
- On The Run - Leigh Daniels, 1989 (Harlequin Intrigue)
- On the Scent - M.J. Rodgers, 1994 (Harlequin Intrigue)
- On The Way To A Wedding - Ingrid Weaver, 1996
- On The Way To The Wedding - Julia Quinn, 2006
- On Thin Ice - Susan Andersen 1995 (Zebra)
- On Wings Of Love - Multiple Authors
- Once A Princess - Multiple Authors
- Once A Thief - Michele Hauf, July 2005 (Silhouette Bombshell #49)
- Once And Again - Brenda Harlen, 2005 (Silhouette Special Edition)
- Once And For Always - Stella Cameron, 1988
- Once He Loves - Sara Bennett, 2003 (Avon)
- Once More, At Midnight - Wendy Warren, 2007 (Silhouette Special Edition)
- Once Upon A Christmas - Multiple Authors
- Once Upon A Pregnancy - Judy Duarte, 2008 (Silhouette Special Edition)
- Once Upon A Rose - Multiple Authors
- Once Upon A Time - Multiple Authors
- One And Only - Multiple Authors
- One And Only, The - Laurie Paige, 2003 (Silhouette Special Edition)
- One Chance At Love - Carole Mortimer, 1988 (Harlequin Presents)
- One Degree of Separation - Fiona Glass, 2005
- One Eye Open - Karen Whiddon, 2004 (Silhouette Intimate Moments)
- One Foot In Heaven - Laraine McDaniel, 1993 (Harlequin American Romance)
- One Forbidden Evening - Jo Goodman, 2006 (Zebra)
- One Good Knight - Mercedes Lackey, 2007 (Luna)
- One Hot Summer - Eve Asbury, 2006 (Whiskey Creek Press)
- One In A Million - Multiple Authors
- One Little Sin - Liz Carlyle, 2005
- One Love for Liv-Marianne Arkins, 2008 (Samhain Publishing)
- One Man's Family - Brenda Harlen, 2007 (Silhouette Special Edition)
- One Man's Folly - Cathy Gillen Thacker, 1989 (Harlequin American Romance)
- One More Chance - Ruth Jean Dale, 1990 (Harlequin Temptation)
- One More Valentine - Anne Stuart, 1993 (Harlequin American Romance)
- One Perfect Man - Lynda Sandoval, 2004 (Silhouette Special Edition)
- One Reckless Night - Sara Craven, 1998 (Harlequin Presents)
- One Silent Night - Multiple Authors
- One Step Ahead - Multiple Authors
- One Summer - Multiple Authors
- One Summer's Day - Catherine Airlie, 1966 (Harlequin Romance)
- One Tough Texan - M.J. Rodgers, 1997 (Harlequin Intrigue)
- One Wild Rose - Geri Borcz, 2002 (Zebra Historical)
- One-Woman Man, A
- # 1 - M.L. Gamble, 1998 (Harlequin Intrigue)
- Only A Memory Away - Madeline St. Claire, 1998 (Harlequin Intrigue)
- Only By Your Touch - Multiple Authors
- Only In My Arms - Jo Goodman, 9/1996, (Zebra)
- Only in Your Arms - Lisa Kleypas, 1995
- Only Love - Elizabeth Lowell, 1995
- Only Man To Trust, The - Grace Green, 1998 (Harlequin Intrigue)
- Only Skin Deep - Rebecca York, 1992 (Harlequin Intrigue)
- Only With A Highlander - Janet Chapman, 2005
- Only With The Heart - Sandra Kitt, 1985 (Harlequin American Romance)
- Only With Your Love - Lisa Kleypas, 1992
- Only Witness, The - Jan Michaels, 1987 (Harlequin Intrigue)
- Only Yesterday - Karen Toller Whittenburg, 1990 (Harlequin Temptation)
- OohRah! - Tilly Greene, 2007
- Opal Fire - Sandy Dengler, 1986
- Opal Fires - Lynda Trent, 1982
- Open Channels - Rebecca Bond, 1986 (Harlequin American Romance)
- Open Hands - Rebecca Flanders, 1985 (Harlequin American Romance)
- Open In Nine Months - Leanna Wilson, 2000 (Harlequin American Romance)
- Open Invitation - Tiffany White, 1989 (Harlequin Temptation)
- Open Invitation? - Karen Kendall, 2005 (Harlequin Blaze)
- Open Marriage, The - Flora Kidd, 1985 (Harlequin Presents)
- Open Not the Door - Katrina Britt, 1978 (Harlequin Romance)
- Open Secret - [[Janice Kay Johnson], 2006 (Harlequin Superromance)
- Open To Influence - Frances Roding, 1988 (Harlequin Presents)
- Opening The Door - Megan Hart, 2004 (Amber Quill Press)
- Operation Bassinet - Joyce Sullivan, 2003 (Harlequin Intrigue)
- Operation: Midnight Cowboy - Linda Castillo, 2007 (Harlequin Intrigue)
- Operation: Midnight Guardian - Linda Castillo, 2006 (Harlequin Intrigue)
- Operation S.N.A.R.E. - Eve Gladstone, 1987 (Harlequin Intrigue)
- Opposites Attract - Multiple Authors
- Orchid Hunter, The - Sandra K. Moore, 2005 (Silhouette Bombshell #35)
- Origin In Death - J.D. Robb, 2005 (Berkley)
- Orphan, The - Stella Cameron, 2002
- Other Brother, The - Janis Reams Hudson, 2004 (Silhouette Special Edition)
- Other Half, The - Jayelle Drewry, 2005 (Liquid Silver Books)
- Other Laura, The - Sheryl Lynn, 1996 (Harlequin Intrigue)
- Other Side Of Paradise, The - Laurie Paige, 2005 (Silhouette Special Edition)
- Other Sister, The - Lynda Sandoval, 2007 (Silhouette Special Edition)
- Other Woman, The - Multiple Authors
- Otherwise Engaged - Suzanne Brockmann, 1997 (Bantam Loveswept)
- Our Husband, Stephanie Bond, 2000 (St. Martin's Press)
- Out From The Shadows - Andrea Davidson, 1986 (Harlequin Intrigue)
- Out Of Control - Multiple Authors
- Out Of Nowhere - Multiple Authors
- Out Of The Blue - Multiple Authors
- Out of the Box - Kallysten, 2007 (Alinar Publishing)
- Out of the Box 2 - Kallysten, 2007 (Alinar Publishing)
- Out Of The Night - Multiple Authors
- Outback Affair, The - Elizabeth Duke, 2000 (Harlequin Romance Subscription)
- Outback Angel - Margaret Way, 2002 (Harlequin Romance)
- Outback Baby - Multiple Authors
- Outback Baby Miracle - Melissa James, 2007 (Harlequin Romance)
- Outback Bridal Rescue, The - Emma Darcy, 2004 (Harlequin Presents)
- Outback Bride - Jessica Hart, 1999 (Harlequin Romance Subscription)
- Outback Bridegroom - Margaret Way, 2003 (Harlequin Romance)
- Outback Engagement, The - Margaret Way, 2005 (Harlequin Romance)
- Outback Husband - Jessica Hart, 2000 (Harlequin Romance)
- Outback Man - Miranda Lee, 1991 (Mills & Boon Romance)
- Outback Man, The - Amanda Doyle, 1966 (Harlequin Romance)
- Outback Man Seeks Wife - Margaret Way, 2007 (Harlequin Romance)
- Outback Marriage Ransom, The - Emma Darcy, 2004 (Harlequin Presents)
- Outback Mistress - Lindsay Armstrong, 2000 (Harlequin Presents)
- Outback Nights - Emilie Richard, 1987 (Silhouette Romance)
- Outback Rainbow - Dorothy Cork, 1978 (Harlequin Romance)
- Outback Runaway - Dorothy Cork, 1980 (Harlequin Romance)
- Outback Wedding Takeover, The - Emma Darcy, 2004 (Harlequin Presents)
- Outback Wife And Mother - Barbara Hannay, 1999 (Harlequin Romance)
- Outback With The Boss - Barbara Hannay, 2001 (Harlequin Romance)
- Outcast, The - Jayelle Drewry, 2006 (Liquid Silver Books)
- Outlander - Diana Gabaldon, 1991 (Dell)
- Outlaw - Multiple Authors
- Outlaw, The - Multiple Authors
- Outlaw Bride - Jenna Kernan, 2008 (Harlequin Historical)
- Outlaw Bride, The - Maggie Shayne, 1999 (Silhouette Intimate Moments)
- Outlaw For Christmas, An - Lori Handeland, 2001 (Zebra)
- Outlawed! - B.J. Daniels, 1996 (Harlequin Intrigue)
- Outrageous - Lori Foster, 1997 (Harlequin Temptation)
- Outside In - Beverly Sommers, 1990 (Harlequin American Romance)
- Outsider - Multiple Authors
- Outsider, The - Multiple Authors
- Outsider's Redemption, The - Joanna Wayne, 2000 (Harlequin Intrigue)
- Over The Edge - Suzanne Brockmann, 2001 (Ivy)
- Over The Moon - MaryJanice Davidson, 2007 (Berkley)
- Overlord's Bride, The - Margaret Moore, 2001 (Harlequin Historical)
- Overnight Male - Elizabeth Bevarly, 2008 (HQN
