Called "AJ" by friends, Budrys was born Algirdas Jonas Budrys in Königsberg in East Prussia. He was the son of the consul general of the Lithuanian government, (the pre-World War II government still recognized after the war by the United States, even though the Soviet-sponsored government was in power throughout most of Budrys's life). His family was sent to the United States by the Lithuanian government in 1936 when Budrys was 5 years old. During most of his adult life, he held a captain's commission in the Free Lithuanian Army.

Budrys was educated at the University of Miami, and later at Columbia University in New York. His first published science fiction story was "The High Purpose", which appeared in Astounding Science Fiction in 1952. Beginning in 1952 Budrys worked as editor and manager for such science fiction publishers as Gnome Press and Galaxy Science Fiction. Some of his science fiction in the 1950s was published under the pen name "John A. Sentry", a reconfigured Anglification of his Lithuanian name. Among his other pseudonyms in the SF magazines of the 1950s and elsewhere, several revived as bylines for vignettes in his magazine Tomorrow Speculative Fiction, is "William Scarff". He also wrote several stories under the names "Ivan Janvier" or "Paul Janvier." He also used the pen name "Alger Rome" in his collaborations with Jerome Bixby.

Budrys's 1960 novella Rogue Moon was nominated for a Hugo Award, and was later anthologized in The Science Fiction Hall of Fame, Volume Two (1973). His Cold War science fiction novel Who? was adapted for the screen in 1973. In addition to numerous Hugo Award and Nebula Award nominations, Budrys won the Science Fiction Research Association's 2007 Pilgrim Award for lifetime contributions to speculative fiction scholarship. In 2009, he was the recipient of one of the first three Solstice Awards presented by the SFWA in recognition of his contributions to the field of science fiction.

Budrys was also a critic for Galaxy Science Fiction, a book editor for Playboy, a longtime teacher at the Clarion Writers Workshop and an organizer and judge for the Writers of the Future awards. In addition, he worked as a publicist; in one publicity stunt, he erected a giant pickle on the proposed site of the Chicago Picasso.

Budrys was married to Edna Duna; they had four sons. He last resided in Evanston, Illinois. He died at home, from metastatic malignant melanoma on June 9, 2008.

Novels

• False Night (1954)
• Man of Earth (1956)
• Who? (1958)
• The Falling Torch (1959)
• Rogue Moon (1960)
• Some Will Not Die (1961) (an expanded and restored version of False Night)
• The Iron Thorn (1967) (as serialized in If; published in book form as The Amsirs And The Iron Thorn). On a bleak forbidding planet, humans hunt Amsirs - flightless humanoid birds - and vice versa. After one young hunter makes his first kill, he's initiated into the society's secrets. Still, he figures there are secrets the human race has forgotten altogether, and begins to hunt for answers.
• Michaelmas (1977)
• Hard Landing (1993)
• The Death Machine (2001) (originally published as Rogue Moon against Budrys's wishes)

Collections (Fiction, Essays, and mixed)

• The Unexpected Dimension (1960)
• Budrys' Inferno (1963)
• The Furious Future (1963)
• Blood and Burning (1978)
• Benchmarks: Galaxy Bookshelf (1984)
• Writing to the Point (1994)
• Outposts: Literatures of Milieux (1996)
• Entertainment (1997)
• The Electric Gene Machine (2000)

Short stories

• "The End of Summer" (1954) in Astounding Science Fiction; also published in the short story anthology Penguin Science Fiction (edited by Brian Aldiss, 1961).

• "Citadel" (1955)

• "The War is Over" ( 1957) - first apperared in "Astounding Science Fiction" Feb. 1957. Also published in the short story anthology "13 Great stories of Science-Fiction" (edited by Groff Conklin, 1960.)

• "The Stoker and the Stars" (as John A. Sentry, in Astounding Science Fiction Feb. 1959)

• "The Price" (1960) — first appeared in The Magazine of Fantasy & Science Fiction, February 1960. Also published in the short story anthology The War Book (edited by James Sallis, 1969).

• "For Love" (originally published in Galaxy Science Fiction, June, 1962) — appears in The Seventh Galaxy Reader edited by Frederik Pohl (Doubleday Science Fiction, 1964).

• "Be Merry" (1966) published in If, December 1966, Vol. 16, No. 12, Issue 109.

• "The Master Of The Hounds" (1966) first published in The Saturday Evening Post and an Edgar Award nominee.

Audio recording

• 84.2 Minutes of Algis Budrys (1995), Unifont (Budrys's own company). Released on cassette, this featured Budrys reading his short stories "The Price", "The Distant Sound of Engines", "Never Meet Again", and "Explosions!".

Magazine

• Tomorrow Speculative Fiction (1993—2000); initially edited by Budrys and published by Pulphouse Publishing, with its second issue it was published and edited by Budrys with assistance from Kandis Elliott under the Unifont rubric. It ceased publication as a paper and ink magazine and became a webzine late in the decade.

Anthologies

• L. Ron Hubbard Presents Writers of the Future, Vol. III (1987)
• L. Ron Hubbard Presents Writers of the Future, Vol. 6 (1990)
• L. Ron Hubbard Presents Writers of the Future, Vol 12 (1996)
• L. Ron Hubbard Presents Writers of the Future Vol. 16 (2000)
• L. Ron Hubbard Presents Writers of the Future, Vol 19 (2003)