Niven is a great-grandson of oil tycoon Edward L. Doheny, an important figure in the Teapot Dome scandal of the 1920s. He briefly attended the California Institute of Technology and graduated with a Bachelor of Arts in mathematics (with a minor in psychology) from Washburn University, Topeka, Kansas, in 1962. He did a year of graduate work in mathematics at the University of California at Los Angeles. He has since lived in Los Angeles suburbs, including Chatsworth and Tarzana, as a full-time writer. He married Marilyn Joyce "Fuzzy Pink" Wisowaty, herself a well-known science fiction and Regency literature fan, on September 6, 1969.

Niven is the author of numerous science fiction short stories and novels, beginning with his 1964 story "The Coldest Place". In this story, the coldest place concerned is the dark side of Mercury, which at the time the story was written was thought to be tidally locked with the Sun (it was found to rotate in a 2:3 resonance after Niven received payment for the story, but before it was published).

In addition to the Nebula award in 1970 and the Hugo and Locus awards in 1971 for Ringworld, Niven won the Hugo Award for Best Short Story for "Neutron Star" in 1967. He won the same award in 1972, for "Inconstant Moon", and in 1975 for "The Hole Man". In 1976, he won the Hugo Award for Best Novelette for "The Borderland of Sol".

Niven has written scripts for various science fiction television shows, including the original Land of the Lost series and The Animated Series, for which he adapted his early story "The Slaver Weapon". He adapted his story "Inconstant Moon" for an episode of the television series The Outer Limits in 1996.

He has also written for the DC Comics character Green Lantern including in his stories hard science fiction concepts such as universal entropy and the redshift effect, which are unusual in comic books. The bible for Green Lantern was written by Niven.

Many of Niven's stories take place in his Known Space universe, in which humanity shares the several habitable solar system nearest to the Sun with over a dozen alien species, including aggressive feline Kzinti and very intelligent but cowardly Pierson's Puppeteers, which are frequently central characters. The Ringworld series is set in the Known Space universe.

The creation of thoroughly worked-out alien species, which are very different from humans both physically and mentally, is recognized as one of Niven's main strengths.

Niven has also written a logical fantasy series The Magic Goes Away, which utilizes an exhaustible resource, called Mana, to power a rule-based "technological" magic.

The Draco Tavern series of short stories take place in a more whimsical science fiction universe, told from the point of view of the proprietor of a multi-species bar.

The whimsical Svetz series consists of a collection of short stories, The Flight of the Horse, and a novel, Rainbow Mars, which involve a nominal time machine sent back to retrieve long-extinct animals, but which goes, in fact, into alternate realities and brings back mythical creatures such as a Roc and a Unicorn.

Much of his writing since the 1970s has been in collaboration, particularly with Jerry Pournelle, Steven Barnes, Brenda Cooper, or Edward M. Lerner.

Niven's most famous contribution to the SF genre is his concept of the Ringworld, a band of approximately the same diameter as Earth's orbit rotating around a star. The idea's genesis came from Niven's attempts to imagine a more efficient version of a Dyson Sphere, which could produce the effect of surface gravity through rotation. Given that spinning a Dyson Sphere would result in the atmosphere pooling around the equator, the Ringworld removes all the extraneous parts of the structure, leaving a spinning band landscaped on the sun-facing side, with the atmosphere and inhabitants kept in place through centrifugal force and 1000 mile high perimeter walls (rim walls). When it was pointed out to Niven that the Ringworld was dynamically unstable, in that once the center of rotation drifted away from the central sun, gravity would pull the ring into contact with the star, he used this as a plot element in the sequel novel, The Ringworld Engineers.

This idea proved influential, serving as an alternative to a full Dyson Sphere that required fewer assumptions (such as artificial gravity) and allowed a day/night cycle to be introduced (through the use of a smaller ring of "shadow squares", rotating between the ring and its sun). This was further developed by Iain M. Banks in his Culture series, which features about 1/100th ringworld—size megastructures called Orbitals that orbit a star rather than encircling it entirely. Alastair Reynolds also uses ringworlds in his 2008 novel House of Suns. The Ringworld-like namesake of the Halo video game series is the eponymous Halo megastructure/superweapon. It is one of the most visible influences of the Ringworld concept on popular culture.

The original release of The Gathering paid homage to Larry Niven on a card called "Nevinyrral's Disk," with Nevinyrral quite obviously "Larry Niven" spelled backwards. Subsequent sets have featured no new cards featuring Nevinyrral, although the character is sporadically quoted on the flavor text of various cards.

In 1967, Niven was one of a number of Science Fiction Writers of America members who purchased ads in sci-fi magazines opposing the Vietnam War.

Niven was an adviser to Ronald Reagan on the creation of the Strategic Defense Initiative anti missile policy, as covered in the BBC documentary Pandora's Box by Adam Curtis.

In 2007, Niven, in conjunction with a group of science fiction writers known as SIGMA, led by Pournelle, began advising the U.S. Department of Homeland Security as to future trends affecting terror policy and other topics.

One of Niven's best known humorous works is "Man of Steel, Woman of Kleenex", in which he uses real-world physics to underline the difficulties of Superman and a human woman (Lois Lane or Lana Lang) mating.

Larry Niven's novels frequently make use of the stasis field concept, which he also popularized.

In several titles and elsewhere Niven employs terms that are double entendre in that they are apparently metaphorical, but are in fact, meant to be taken literally, or sometimes vice versa. A few examples of this are:

• The novel Destiny's Road is in fact about a road on a planet called Destiny.
• In the Ringworld's past there was an event known as "The Fall of the Cities", in which floating cities literally fell out of the sky and crashed to the ground.
• In his short story, "At the Core", his albino hero Beowulf Shaeffer begins a trip to the Galactic core, but eventually has to turn back because the galactic center is in fact exploding, and sending a deadly wave of hard radiation before it, which prompts some ruminations on cowardice, and yields the revelation at the end of story that the phrase in the title had been meant metaphorically after all.
• The short story "There is a Tide" begins by speaking of a metaphorical tide of fate which guides one's destiny, but the existence of literal tides on a planet in the story is a key to the plot.
• The novel The Integral Trees features long straight floating trees which are curved at each end in opposite directions, giving them the shape of the mathematical integral sign, but are themselves integral to the life cycle of the inhabitants.
• The novel Footfall at first seems to refer to the elephantine Fithp invaders striding across the Earth, but is actually revealed to be the aliens dropping an asteroid nicknamed the Foot onto the Earth.
• The title of the short story "Locusts" continues this theme.

Larry Niven is also known in science fiction fandom for "Niven's Law": There is no cause so right that one cannot find a fool following it. Over the course of his career Niven has added to this first law a list of Niven's Laws which he describes as "how the Universe works" as far as he can tell.

Known Space

• World of Ptavvs (1966)
• A Gift from Earth (1968)
• Neutron Star (collection) (1968)
• The Shape of Space (collection) (1969)
• Protector (1973)...Hugo and Locus SF Awards nominee, 1974
• Tales of Known Space: The Universe of Larry Niven (collection) (1975)
• The Long Arm of Gil Hamilton (short story collection) (1976)
• The Patchwork Girl (1980)
• Three Books of Known Space (omnibus) (1989)
• World of Ptavvs / A Gift From Earth / Neutron Star (omnibus) (1991)
• Crashlander: The Collected Tales of Beowulf Shaeffer (1994)
• Flatlander: The Collected Tales of Gil 'the Arm' Hamilton (omnibus) (1995)
• Fleet of Worlds Larry Niven and Edward M. Lerner (2007)
• Juggler of Worlds Larry Niven and Edward M. Lerner (2008)
• Destroyer of Worlds Larry Niven and Edward M. Lerner (2009)
• Betrayer of Worlds Larry Niven and Edward M. Lerner (2010)

Ringworld

1. Ringworld (1970)... Nebula Award, 1970 Hugo and Locus SF Awards winner, 1971
2. The Ringworld Engineers (1980)...Hugo and Locus SF Awards nominee, 1981
• Guide to Larry Niven's Ringworld (1994) (with Kevin Stein)
3. The Ringworld Throne (1996)
4. Ringworld's Children (2004)

Man-Kzin anthologies

1. Man-Kzin Wars (1988)
2. Man-Kzin Wars II (1989)
3. Man-Kzin Wars III (1990)
4. Man-Kzin Wars IV (1991)
5. Man-Kzin Wars V (1992)
6. Man-Kzin Wars VI (1994)
7. Man-Kzin Wars VII (1995)
8. Man Kzin Wars VIII: Choosing Names (1998)
9. Man-Kzin Wars IX (2002)
10. The Wunder War (2003)
11. Man-Kzin Wars XI (2005)
12. Destiny's Forge (2007)
13. Man-Kzin Wars XII (2009)

With Jerry Pournelle

• Inferno (1976)...Hugo and Nebula Awards nominee, 1976
• Lucifer's Hammer (1977)...Hugo Award nominee, 1978
• Oath of Fealty (1982)
• Footfall (1985)...Hugo and Locus SF Awards nominee, 1986
• Escape from Hell (2009, sequel to Inferno)
• Moties
• The Mote in God's Eye (1974)...Hugo, Nebula and Locus SF Awards nominee, 1975
• The Gripping Hand aka The Moat Around Murcheson's Eye (1993)
• Golden Road (set in the same fantasy world as The Magic Goes Away)
• The Burning City (2000)
• Burning Tower (2005)
• Burning Mountain (in progress)
• Heorot (with Steven Barnes and Jerry Pournelle)
• The Legacy of Heorot (1987)
• Beowulf's Children (1995 UK as The Dragons of Heorot)
• Destiny's Road (1997) (Written alone by Niven, not precisely a continuation of the Heorot series. Located in the same universe...events from the first two novels are briefly mentioned.)

Dream Park (with Steven Barnes)

1. Dream Park (1981)...Locus SF Award nominee, 1982
2. The Barsoom Project (1989)
3. The California Voodoo Game aka The Voodoo Game (1992)
4. The Descent of Anansi (1982)
5. Achilles' Choice (1991)
6. Saturn's Race (2001)

The State

1. A World Out of Time (1976)...Locus SF Award nominee, 1977
2. The Integral Trees (1984)...Nebula Award nominee, 1984; Locus SF Award winner, and Hugo nominee, 1985
3. The Smoke Ring (1987)

Magic Goes Away

1. Not Long Before The End (1969)
2. What Good is a Glass Dagger? (1972)
3. The Magic Goes Away (1978)
4. The Magic May Return (1981)
5. More Magic (1984)
6. The Time of the Warlock (Greendragon Press)(1984)
• The Magic Goes Away Collection (omnibus) (2005)

Graphic novels and comics

• Illustrated Adaptation of the Larry Niven Novella (1991)
• Ganthet's Tale (1992, DC Comics, ISBN 1-56389-026-7) (with John Byrne)
• The Magic Goes Away, graphic novel illustrated by Jan Duursema, DC Comics
• "Not Long before the End" was adapted by Doug Moench and Vicente Alcazar, and "All the Myriad Ways" by writer-artist Howard Chaykin, both for Marvel Comics' black-and-white anthology magazine Unknown Worlds of Science Fiction.

Short story collections

• All the Myriad Ways (1971)
• The Flight of the Horse (1973)
• Inconstant Moon (1973)
• A Hole in Space (1974)
• Convergent Series (1979)
• Niven's Laws (1984)
• Limits (1985)
• N-Space (1990)
• Playgrounds of the Mind (1991)
• Bridging the Galaxies (1993)
• Crashlander (1994)
• Scatterbrain (2003)
• Larry Niven Short Stories Volume 1 (2003)
• Larry Niven Short Stories Volume 2 (2003)
• Larry Niven Short Stories Volume 3 (2003)
• The Draco Tavern (2006)
• Stars and Gods (August 2010, ISBN 0-765-30864-9)

Other novels

• The Flying Sorcerers (with David Gerrold) (1971) [previously serialised as "The Misspelled Magishun", it is recursive, and includes portraits of other SF authors...e.g. the lead character name becomes translated into the local language as "As a color, shade of purple-gray" (or Purple for short), that is, "As-A-Mauve"
• A Collaborative Novel (1984) (with Poul Anderson, Edward Bryant, Stephen R. Donaldson, Fred Saberhagen, Connie Willis and Roger Zelazny)
• Fallen Angels (1991) (with Jerry Pournelle and Michael Flynn)
• Rainbow Mars (1999)
• Building Harlequin's Moon (2005) (with Brenda Cooper)