- An Ideal Husband - Oscar Wilde
- An Ideal Husband.
- An Idle King
- An Idyllic Place for Murder
- An Illegal President: A Novel
- An Illustrated History of the Police Service in Northern Ireland and its Forerunners
- An Image in the Lake
- An Immigrant
- An Impartial Witness
- An Imperfect Killing
- An Imperfect Oath
- An Impossible Abduction
- An Impossible Impostor
- An Inch Of Fortune
- An Inch of Time
- An Incident at First and Fifth
- An Inconvenient DEADline
- An Inconvenient Death
- An Inconvenient Duke
- An Inconvenient Woman
- An Incursion of Mice
- An Indian Legacy
- An Individual Will
- An Infectious Game
- An Infinite Game
- An Infinite Number of Monkeys
- An Inheritance To Die For
- An Inner Fire
- An Innocent Addiction
- An Innocent Among Them
- An Innocent Lie
- An Innocent Mans Revenge
- An Inside Job
- An Insomniacs Dream
- An Inspector Calls
- An Instance of the Fingerpost
- An Instant Confection
- An Intangible Affair
- An Interlude
- An Interlude in Berlin
- An Interlude In Dreamland
- An International Affair
- An Interrupted Performance
- An Interview With Cynthia Masters
- An Intimate Deception
- An Intimate Murder
- An Intimate Study of Sherlock Holmes
- An Intimate Study of Sherlock Holmes (Conan Doyle's thoughts about Sherlock Holmes)
- An Irish Ghost Story: A Kate Ryan Mystery
- An Irish Hostage
- An Irish Nor'easter
- An Irish Solution
- An Iron Fist, Two Harbors
- An Irresistible Alliance
- An Island To Die For
- An jenem dunklen Tag
- An Oasis of Horror
- An Oath of Dogs
- An Obsession with Death and Dying: Volume One
- An Obsession with Death and Dying: Volume Two
- An Obvious Enchantment
- An Occasional Hell
- An Ocracoke Affair
- An OD Out Stickney
- An Odder Quintet
- An Officer and a Hitman
- An Officer and a Spy
- An Official Killing
- An Oktoberfest Death
- An Old Chaos
- An Old Fashioned Murder Mystery
- An Old Grudge
- An Old Fashioned Murder Mystery
- An Old Grudge
- An Old Lady Dies
- An Old Money Murder in Mayfair
- An Old Remedy
- An Old School Tie
- An Old Shadow
- An Old Shrew, a Tortured Soul, and Everyday Angels
- An Old-Fashioned War
- An Ominous Death
- An Open Book
- An Open Book: A Mystery
- An Open Prison
- An Open Spook
- An Opening In the Wall
- An Ordinary Day
- An Ordinary Decent Criminal
- An Ordinary Person
- An Ordinary Treasure Hunt
- An Oriel of Death
- An Origin Tail
- An Ostentation
- An Ounce of Hope: A Pound of Flesh Book 2
- An Outer Banks Vacation
- An Outpost of Progress
- An Overdose Of Truth
- An Overdue Truce
- An Overnight Sensation
- An Overture Sinister
- An Oxford Tragedy
- An Tearmann
- An tIriseoir
- An Uncertain Faith
- An Uncertain Place
- An Uncharted Corpse