Series

Lord Darcy

• Murder and Magic (1979, collection of 1964—1973 stories)
• Too Many Magicians (1966, magazine serialization 1966)
• Lord Darcy Investigates (1981, collection of 1974—1979 stories)
• Lord Darcy (1983) (this omnibus contains the contents of the three books above; 2002 edition adds 2 uncollected stories, with minor editing to remove repetitions of the backstory)

with Robert Silverberg, as Robert Randall

• The Shrouded Planet (1957)
• The Dawning Light (1959)

with Laurence M. Janifer, as Mark Phillips

• Brain Twister (1962) [2]
• The Impossibles (1963) [3]
• Supermind (1963) [4]

The Gandalara Cycle with Vicki Ann Heydron

• The Steel of Raithskar (1981)
• The Glass of Dyskornis (1982)
• The Bronze of Eddarta (1983)
• The Well of Darkness (1983)
• The Search for Ka (1984)
• Return to Eddarta (1984)
• The Gandalara Cycle I (omnibus; contains The Steel of Raithskar, The Glass of Dyskornis, The Bronze of Eddarta.) (1986)
• The Gandalara Cycle II (omnibus; contains The Well of Darkness, The Search for Ka, Return to Eddarta.) (1986)
• The River Wall (1986)

Novels

• Pagan Passions (1959) (with Laurence Janifer as "Larry M. Harris")[5]
• Unwise Child (1962) [6]
• Anything You Can Do (1963) (as Darrel T. Langart) [7]

Collections

• Takeoff! (1980), composed of tongue-in-cheek imitations of a number of other authors and universes, such as E.E. "Doc" Smith's Lensman series and Reginald Bretnor's Ferdinand Feghoot (who is "Benedict Breadfruit" in Garrett's treatment).
• The Best of Randall Garrett (1982) (edited by Robert Silverberg)
• Takeoff Too! (1987)
• A Little intelligence (2009; with Robert Silverberg, a collection of their early science-fctional mystery stories)

Notable short fiction

• "Probability Zero" (1944) first published science fiction story.
• "The Best Policy" (1957), in which a smart Earthling manages to convince a reconnaissance group of hostile aliens who abduct him that the earthlings are far more advanced and superior race, and instead of a hostile takeover, they send humble ambassadors. The catch is the aliens have a perfect truth detector and the hero has to phrase every line carefully so that while being literally honest he can pull off such a huge lie.
• "Despoilers of the Golden Empire" (1958) [8], in which he spun a pulp yarn of space flight, swordplay, and derring-do, only to reveal it to be a deception, an account of the conquest of Peru by Francisco Pizarro with careful misdirection in the text.

Novels and anthologies

• A Case of Identity 1964 (a Lord Darcy story)
• A Matter of Gravity 1974 (a Lord Darcy story)
• A Stretch of the Imagination 1973 (a Lord Darcy story)
• All the King's Horses with Robert Silverberg as Robert Randall 1958
• Anything You Can Do as Darrel T.Langart 1963 ( Novel)
• Brain Twister 1962 expansion of That Sweet Little Old Lady 1959 with Laurence M. Janifer as Mark Phillips ( Short Version) ( Novel)
• False Prophet with Robert Silverberg as Robert Randall
• Lord Darcy 1983 (Lord Darcy omnibus)
• Lord Darcy Investigates 1981 (a Lord Darcy collection)
• Murder and Magic 1979 (a Lord Darcy collection)
• Pagan Passions with Larry M. Harris 1959 [9]
• Return to Eddarta with Vicki Ann Heydron 1985
• Supermind 1963 previously published as Occasion for Disaster 1960 with Laurence M. Janifer as Mark Phillips ( Occasion for Disaster 1960) ( Supermind 1963)
• Takeoff! 1980
• Takeoff Too 1987
• The Absence of Heat 1944
• The Best of Randall Garrett with Robert Silverberg 1982
• The Bronze of Eddarta with Vicki Ann Heydron 1983
• The Chosen People with Robert Silverberg as Robert Randall 1956
• The Dawning Light with Robert Silverberg as Robert Randall 1959
• The Eyes Have It 1964 (a Lord Darcy story) [10]
• The Glass of Dyskornis with Vicki Ann Heydron 1982
• The Impossibles 1963 previously published as Out Like a Light 1960 with Laurence M. Janifer as Mark Phillips ( Out Like a Light 1960) ( The Impossibles 1963)
• The Ipswich Phial 1976 (a Lord Darcy story)
• The Muddle of the Woad 1965 (a Lord Darcy story)
• The Napoli Express 1979 (a Lord Darcy story)
• The Promised Land with Robert Silverberg as Robert Randall
• The River Wall with Vicki Ann Heydron 1986
• The Search for Ka with Vicki Ann Heydron 1984
• The Shrouded Planet with Robert Silverberg as Robert Randall 1957
• The Sixteen Keys 1976 (a Lord Darcy story)
• The Spell of War 1978
• The Steel of Raithskar with Vicki Ann Heydron 1981
• The Well of Darkness with Vicki Ann Heydron 1983
• Too Many Magicians 1967 (a Lord Darcy novel)
• Unwise Child also published as Starship Death 1962 [11]

• A Fortnight of Miracles 1965
• A Little Intelligence with Robert Silverberg as Robert Randall 1958
• A Pattern for Monsters 1957
• A Spaceship Named McGuire 1961 [12]
• A Trip to Anywhen as Ivar Jorgensen 1956
• A World by the Tale as Seaton McKettrig 1963 [13]
• All About "The Thing" also published as Parodies Tossed 1956
• Anchorite as Johnathan Blake MacKenzie 1962 [14]
• And Check the Oil 1958
• And Then He Was Two as Ivar Jorgensen 1957
• Anything You Can Do as Darrell T.Langart 1962 Short Version
• Backstage Lensman 1978
• Backward, Turn Backward 1959
• Belly Laugh as Ivar Jorgensen 1953 [15]
• Blaze of Glory 1955
• Blessed Are the Murderous as Ivar Jorgensen 1954
• But, I Don't Think 1959 [16]
• By Proxy as David Gordon 1960 [17]
• Calling Captain Flint with Robert Silverberg as Richard Greer 1956
• Catch a Thief with Robert Silverberg as Gordon Aghill 1956
• Color Me Deadly 1973
• Cum Grano Salis as David Gordon 1959 [18]
• Damned If You Don't 1960 [19]
• Dead Giveaway 1959 [20]
• Death to the Earthman 1956
• Despoilers of the Golden Empire as David Gordon 1959 [21]
• El Ropo Tarkas (poem) 1978
• Engineer's Art 1961
• Fifty Per Cent Prophet as Darrell T.Langart 1961 [22]
• Fighting Division 1965
• Fimbulsommer with Michael Kurland 1970
• Frost and Thunder 1979
• Gambler's Planet with Robert Silverberg as Gordon Aghill 1956
• Please Note 1957
• Gift from Tomorrow 1957
• Hail to the Chief 1962 [23]
• Hanging by a Thread as David Gordon 1961 [24]
• Heist Job on Thizar 1956 [25]
• Hepcats of Venus also published as The Cosmic Beat 1962
• His Master's Voice 1962
• Hot Argument 1960
• In Case of Fire 1960 [26]
• Infinite Resources 1954
• I've Got a Little List 1953
• Just Another Vampire Story 1979
• Keepersmith with Vicki Ann Heydron 1979
• La Difference 1962
• Lauralyn 1977
• Look Out! Duck! as David Gordon 1957
• Lord Darcy Investigates 1981
• Machine Complex 1956
• Masters of the Metropolis with Lin Carter 1957
• Murder and Magic 1979 (a Lord Darcy story)
• Mustang 1961
• Needler 1957
• No Connections 1958
• Nor Iron Bars A Cage ... as Johnathan Blake MacKenzie 1962 [27]
• Occasion for Disaster later published as Supermind with Laurence M. Janifer as Mark Phillips 1960 [28]
• On the Martian Problem 1977
• Or Your Money Back as David Gordon 1959 [29]
• Out Like a Light with Laurence M. Janifer as Mark Phillips 1960 [30]
• Overproof as Johnathan Blake MacKenzie 1965
• Penal Servitude 1958
• Pest with Lou Tabakow 1952
• Plague Planet as Ivar Jorgensen 1955
• Polly Plus 1978
• Pop! 1960
• Prehistoric Note 1979
• Pride and Primacy 1974
• Psichopath as Darrell T.Langart 1960 [31]
• Puzzle in Yellow 1956
• Quest of the Golden Ape as Ivar Jorgensen with Milton Lesser as Adam Chase 1957
• Quick Cure 1956
• Random Choice 1961
• Reading the Meter 1974
• Ready, Aim, Robot! 1959
• Reviews in Verse 1980
• Small Miracle 1959
• Something for the Woman as Ivar Jorgensen 1953
• Something Rich and Strange with Avram Davidson 1961
• Sound Decision with Robert Silverberg 1956
• Spatial Delivery 1954
• Spatial Relationship 1962
• Suite Mentale 1956 [32]
• The Adventures of "Little Willie" 1980
• The Asses of Balaam as David Gordon 1961 [33]
• The Beast with Seven Tails with Robert Silverberg as Leonard G. Spencer 1956
• The Best Policy as David Gordon 1957
• The Bitter End 1978 (a Lord Darcy story)
• The Blaze of Noon with Avram Davidson 1961
• The Bramble Bush 1962 [34]
• The Briefing 1969
• The Day the Gods Fell as Ivar Jorgensen 1953
• The Deadly Sky as Ivar Jorgensen 1971
• The Destroyers 1959 [35]
• The Final Fighting of Fion Mac Cumhaill 1975
• The Foreign Hand-Tie as David Gordon 1961 [36]
• The Genius as Ivar Jorgensen 1955
• The Girl from Bodies, Inc. with Robert Silverberg as Leonard G. Spencer 1956
• The Great Kladnar Race with Robert Silverberg as Richard Greer 1956
• The Highest Treason 1961 [37]
• The Horror Out of Time 1978
• The Hunting Lodge 1954
• The Judas Valley with Robert Silverberg as Gerald Vance 1956 [38]
• The Man who Collected Women 1957
• The Man who Hated Mars 1956 [39]
• The Man Who Knew Everything 1956
• The Man who Talked to Bees as Ivar Jorgensen 1955
• The Measure of A Man 1960 [40]
• The Mummy Takes a Wife with Robert Silverberg as Clyde Mitchell 1956
• The Penal Cluster as Ivar Jorgensen 1957 [41]
• The Queen Bee 1958
• The Secret of the Shan with Robert Silverberg as Richard Greer 1957
• The Slow and the Dead with Robert Silverberg as Robert Randall 1956
• The Spell of War 1978 (a Lord Darcy story)
• The Unnecessary Man 1959 [42]
• The Vengeance of Kyvor 1957
• The Waiting Game 1951
• The Wishing Stone as Ivar Jorgensen 1953
• There's No Fool as David Gordon 1956
• Thin Edge as Johnathan Blake MacKenzie 1963 [43]
• Through Time and Space with Benedict Breadfruit I-VIII as Grandall Barretton 1962
• Time Fuze 1954
• Tin Lizzie 1964
• Two to the Stars as Ivar Jorgensen 1955
• Viewpoint 1960 [44]
• What the Left Hand Was Doing as Darrell T.Langart 1960 [45]
• What's Eating You? 1957
• With All the Trappings 1956
• With No Strings Attached as David Gordon 1963 [46]
• Witness for the Persecution 1966
• Zap! 1962