This is a list of characters in the fiction of Robert A. Heinlein:

A

• Allucquere (a.k.a. "Mary") – The Puppet Masters
• Security Chief Juan Alvarez – The Moon Is a Harsh Mistress
• Richard Ames (a.k.a. Colin Campbell) – The Cat Who Walks Through Walls
• Sam Anderson – Starman Jones
• Anne (Fair Witness) – Stranger in a Strange Land
• Major Ardmore – Sixth Column
• Pallas Athene, intelligent computer, came to life after the original personality (Minerva) transferred to become a human woman – Time Enough for Love, The Cat Who Walks Through Walls, To Sail Beyond the Sunset

B

• Dr. Hartley M. Baldwin (a.k.a. Gregory "Kettle Belly" Baldwin, "Mr. Two-Canes", "Doc") – Gulf, Friday, The Cat Who Walks Through Walls, Logic of Empire
• Col. Richard Baslim (a.k.a. "Baslim the Cripple") – Citizen of the Galaxy
• Thorby Baslim (a.k.a. Thor B. Rudbek, "Rudbek of Rudbek at Rudbek") – Citizen of the Galaxy
• Gillian Boardman (Jill) – Stranger in a Strange Land
• Joseph Bonforte – Double Star
• Eunice Branca – I Will Fear No Evil
• Jacob Burroughs – The Number of the Beast, The Cat Who Walks Through Walls
• Hilda Burroughs (nee Hilda "Sharpie" Corners) – The Number of the Beast, The Cat Who Walks Through Walls, To Sail Beyond the Sunset
• Thomas and Patrick Bartlett – Time for the Stars

C

• Colonel Colin Campbell (a.k.a. Richard Ames) – The Cat Who Walks Through Walls
• Dejah Thoris "Deety" Burroughs Carter – The Number of the Beast, The Cat Who Walks Through Walls
• Zebadiah John Carter – The Number of the Beast, The Cat Who Walks Through Walls
• Ben Caxton – Stranger in a Strange Land
• Eldreth Coburn – Starman Jones
• Grace Cormet – We Also Walk Dogs
• Hilda Corners – see Hilda Burroughs
• Ed Cowen – The Star Beast
• Cynthia Craig – The Unpleasant Profession of Jonathan Hoag
• Cuddlepup – The Star Beast

D

• John "Johnny" Ezra Dahlquist – "The Long Watch". Referred to as Ezra Dahlquist in Space Cadet.
• Daniel Boone Davis – The Door into Summer
• Hazel Meade Davis (Sadie Lipschitz) (Gwendolyn Novak) The Cat Who Walks Through Walls (see also Hazel Stone below)
• Manuel Garcia O'Kelly Davis (Mannie) – The Moon Is a Harsh Mistress, The Cat Who Walks Through Walls
• Doctor-Livingston-I-Presume (cat) – Farnham's Freehold
• Matt Dodson – Space Cadet
• Dora (computer) – Time Enough for Love, The Number of the Beast, The Cat Who Walks Through Walls
• Dora Smith (Adorable Dora) (Dorable) – Time Enough for Love
• Dorcas – Stranger in a Strange Land
• Dr. Archibald Douglas – Let There Be Light
• Chief Dreiser – The Star Beast

F

• Duke Farnham – Farnham's Freehold
• Grace Farnham – Farnham's Freehold
• Hugh Farnham – Farnham's Freehold
• Karen Farnham – Farnham's Freehold
• Justin Foote – Methuselah's Children
• Justin Foote 45th – Time Enough for Love, The Cat Who Walks Through Walls
• Friday a.k.a. Marjorie Baldwin – Friday
• Clark Fries – Podkayne of Mars
• Podkayne Fries – Podkayne of Mars
• Dr. Ftaeml – The Star Beast
• Fuzzy Britches (flat cat) – The Rolling Stones

G

• Larry Gaines – The Roads Must Roll
• Galahad – Time Enough for Love
• Gay Deceiver – The Number of the Beast, To Sail Beyond the Sunset, The Cat Who Walks Through Walls
• Gekko – Red Planet
• Frederica "Ricky" Gentry – The Door into Summer
• Alec Graham / Alex Hergensheimer – Job: A Comedy of Justice
• Joe Green – Gulf
• Sergei Greenberg – The Star Beast
• Joe-Jim Gregory – Orphans of the Sky
• Oscar Gordon – Glory Road (also appears briefly in The Number of the Beast)

H

• Delos D. Harriman – The Man Who Sold the Moon, Requiem, To Sail Beyond the Sunset
• Jubal Harshaw – Stranger in a Strange Land, The Number of the Beast, The Cat Who Walks Through Walls, To Sail Beyond the Sunset, Citizen of the Galaxy (as James J. Garsh)
• Don Harvey – Between Planets
• Gretchen Henderson, daughter of Ingrid and Jinx Henderson – The Moon Is a Harsh Mistress, The Cat Who Walks Through Walls, To Sail Beyond the Sunset
• Ingrid Henderson Jinx Henderson's wife, direct descendant of Hazel Stone – The Cat Who Walks Through Walls
• Jinx Henderson, born John Black Eagle, took Ingrid Henderson's surname when he married her – The Cat Who Walks Through Walls
• Wolf Henderson, Ingrid and Jinx Henderson's son – The Cat Who Walks Through Walls
• Alex Hergensheimer / Alec Graham – Job: A Comedy of Justice
• Mortimer "Mort the Wart" Hobart – The Moon Is a Harsh Mistress
• Mycroft "Mike" Holmes (a.k.a. Adam Selene, Mychelle Holmes) – The Moon Is a Harsh Mistress
• Myra Holtz – The Star Beast
• Ira Howard – Methuselah's Children
• Jonathan Hoag – The Unpleasant Profession of Jonathan Hoag
• Hugh Hoyland – Orphans of the Sky

J

• William 'Tex' Jarman – Space Cadet
• Oscar Jensen – Space Cadet
• Maureen Johnson – see Maureen Johnson Smith, below
• Joseph – Farnham's Freehold
• Max Jones – Starman Jones
• Zebadiah Jones – If This Goes On—

K

• Karen – Gulf
• Henry Gladstone Kiku – The Star Beast
• Wyoming "Wyoh" Knott – The Moon Is a Harsh Mistress

L

• Stuart Rene LaJoie – The Moon Is a Harsh Mistress
• Andrew Jackson Libby, later Elizabeth A. J. Libby Long – Misfit, Methuselah's Children, Time Enough for Love, The Cat Who Walks Through Walls. Also known as "Slipstick" Libby, and in Misfit, has the nickname "Pinky". The Number of the Beast
• Elizabeth Andrew Jackson Libby Long (originally Andrew Jackson Libby) – The Number of the Beast a.k.a. "Pinky" and "Slipstick"
• Maureen Johnson Smith Long – see Maureen Johnson Smith, below
• Lapis Lazuli Long – Time Enough for Love, The Number of the Beast
• Llita – Time Enough for Love
• Lazarus Long (a.k.a. Woodrow Wilson Smith) – Methuselah's Children, Time Enough for Love, The Number of the Beast, The Cat Who Walks Through Walls, To Sail Beyond the Sunset
• Lorelei Lee Long – Time Enough for Love, The Number of the Beast
• Lummox – The Star Beast
• John Lyle – If This Goes On—

M

• Mr. MacClure – The Star Beast
• Dr. Mahmoud (a.k.a. "Stinky") – Stranger in a Strange Land
• Margrethe – Job: A Comedy of Justice
• Jim Marlowe – Red Planet
• Dr. Mary Lou Martin – Let There Be Light
• Mary (a.k.a. "Allucquere") – The Puppet Masters
• Helen Mayberry – Time Enough for Love
• Gloria McNye – "Delilah and the Space Rigger"
• Memtok – Farnham's Freehold
• Minerva – intelligent computer used to run the planet Secundus, later transformed into a human woman – Time Enough for Love, The Cat Who Walks Through Walls, To Sail Beyond the Sunset
• Miriam – Stranger in a Strange Land
• Frank Mitsui – Sixth Column
• Mycroft – see Mycroft "Mike" Holmes, above, The Moon Is a Harsh Mistress
• Mother Thing – Have Space Suit—Will Travel

N

• Nehemiah Scudder – Logic of Empire
• Andrew Nivens, a.k.a. "The Old Man" – The Puppet Masters (his name is not mentioned, only inferred – the President calls him Andrew and his son's last name is Nivens)
• Elihu Nivens, a.k.a. Sam Cavanaugh – The Puppet Masters
• Gwen Novak – The Cat Who Walks Through Walls
• Dr. Sven Nelson – Stranger in a Strange Land

O

• Judge O'Farrell – The Star Beast

P

• Bernardo de la Paz (Prof) – The Moon Is a Harsh Mistress
• Patty Paiwonski – Stranger in a Strange Land
• Penny – Double Star
• Petronius The Arbiter a.k.a. Pete (cat) – The Door into Summer
• Peewee – Have Space Suit—Will Travel
• Longcourt Phyllis – Beyond This Horizon
• Hugo Pinero – Life-Line
• Pixel (cat) – The Cat Who Walks Through Walls, To Sail Beyond the Sunset
• Ponse, The Lord Protector – Farnham's Freehold
• Pug – Glory Road

R

• Random Numbers (Cat) – To Sail Beyond the Sunset
• Rhysling, "Blind singer of the spaceways" – The Green Hills of Earth, Time Enough for Love
• Juan Rico – Starship Troopers
• Wes Robbins – The Star Beast
• Rufo – Glory Road, The Cat Who Walks Through Walls
• Clifford "Kip" Russell – Have Space Suit—Will Travel

S

• Nehemiah Scudder – If This Goes On—
• Johann Sebastian Bach Smith (later Joan Eunice Smith Solomon) – I Will Fear No Evil
• Sister Maggie – If This Goes On—
• Maureen Johnson Smith – Time Enough for Love, The Cat Who Walks Through Walls, To Sail Beyond the Sunset, The Number of the Beast
• Valentine Michael Smith – Stranger in a Strange Land
• Woodrow Wilson Smith – birth name of Lazarus Long (see above)
• Lawrence Smythe (The Great Lorenzo) – Double Star
• Jacob Moshe Solomon – I Will Fear No Evil
• Betty Sorenson – The Star Beast
• Mary Sperling – Methuselah's Children, Time Enough for Love
• Star, a.k.a. Her Wisdom – Glory Road, The Cat Who Walks Through Walls
• Lowell "Buster" Stone – The Rolling Stones, The Cat Who Walks Through Walls (inferred; "Hazel's youngest grandson" is the doctor treating Richard)
• Castor Stone – The Rolling Stones, The Number of the Beast, The Cat Who Walks Through Walls
• Edith Stone – The Rolling Stones
• Hazel Stone – The Rolling Stones, The Moon Is a Harsh Mistress, The Number of the Beast, The Cat Who Walks Through Walls (see also Hazel Meade Davis, above)
• Meade Stone – The Rolling Stones
• Pollux Stone – The Rolling Stones, The Number of the Beast, The Cat Who Walks Through Walls
• Roger Stone - The Rolling Stones
• John Thomas Stuart – The Star Beast

T

• John Thomas – The Star Beast
• Dejah Thoris – see Dejah Carter, above
• Colonel Towers – The Long Watch

V

• Becky Vesey (a.k.a. Madame Alexandra Vesant) – Stranger in a Strange Land
• "Shorty" Van Kleeck – The Roads Must Roll

W

• Rod Walker – Tunnel in the Sky
• Ira Weatheral – Time Enough for Love
• Barbara Wells – Farnham's Freehold
• Willis (Bouncer) – Red Planet
• Wingate – Logic of Empire

Z

• Charles Zim – Starship Troopers