Theodore Sturgeon was considered one of the most influential writers of the so-called "Golden Age" of science fiction fostered by editor John Campbell from 1938 to 1950. Sturgeon was particularly appreciated for his literary style, his attention to character and his treatment of important social issues such as sex, war, and the alienation of those felt to be different from the norm. His depictions of the American working class and his sensitivity to strange and disabled people have been likened to Flannery O'Connor, Sherwood Anderson, and William Faulkner. In his obituary, the New York Times said that "Sturgeon was, in several senses, the conscience of modern science fiction," and Kurt Vonnegut called him "One of the best writers in America…certain to fascinate all sorts of readers, not only science fiction fans." His work is beloved by younger generations of writers as well, including James Tiptree, Jr., Connie Willis, Samuel R. Delany, Michael Chabon, Jonathan Lethem and Nalo Hopkinson.

Sturgeon was born on Staten Island, New York on February 26, 1918 and died in Eugene, Oregon, on May 8, 1985. A resident of New York City; Woodstock, New York; Los Angeles; and Springfield, Oregon, he was the author of more than thirty novels and short story collections. He won the International Fantasy Award for his novel More Than Human; the Hugo Award and Nebula Award for his short story Slow Sculpture; the Outstanding Achievement Award from the International Society of Science Fiction, Horror and Fantasy for the Star Trek screenplay, Amok Time; and the Gaylactica/Spectrum Award for his ground-breaking story about homosexuality, The World Well Lost. For the influence on comic books of his short story It, he won the Inkpot Award. His idea of "bleshing" (the interaction of different individuals in a gestalt, from More Than Human) was influential for performers from The Grateful Dead to the Blue Man Group, scientists such as Carl Sagan and Marvin Minsky, countless writers, and the 60s counterculture in general. Kurt Vonnegut has said Sturgeon was in some ways a model for his notorious fictional character, Kilgore Trout. His lifetime friendship with his contemporary, Robert Heinlein, left traces in their work; Heinlein's name for robots, "waldoes" is a homage to Sturgeon, whose original last name was Waldo. Sturgeon's work presaged the invention of Velcro, the discovery of the double helix in DNA, the AIDS virus, and the impact of psychedelics. He is also known for Sturgeon's Law ("90% of everything is crap") and the credo "Ask the next question." He was an extensive reviewer and teacher of science fiction. For his lifetime of work, he was awarded a World Fantasy Achievement Award, and was inducted into the Science Fiction Hall of Fame in 2000.

Sturgeon's work has appeared on both the small and large screens. Sturgeon wrote three Star Trek screenplays: "Shore Leave" aired on 12/29/66; "Amok Time" aired on 9/15/67; and "The Joy Machine," which was never aired but was later expanded and published as a book written by James Gunn. Amok Time is famous for giving Spock a sex life and inventing the "Live long and prosper" Vulcan greeting. Additionally, he optioned his writing many times, especially his novel More Than Human. In fact, he spent two weeks working with Orson Welles in an attempt to produce a treatment for More Than Human; but this arrangement fell through. (More Than Human was optioned repeatedly from this period until 2000, but a movie has never been made.) In 1974, a TV movie, Killdozer!, was made from the short story of the same name, and in 1975, Sturgeon wrote an episode, "The Pylon Express," for the series Land of the Lost. In 1974, a French film was made of Sturgeon's short story, "Bright Segment," directed by Christian Chalonge. Parcelles Brilliante aired that year on the French TV series Histoires Insolites, and the film was often used by Sturgeon in his writing classes. Two Twilight Zone episodes were aired in 1986, "A Saucer of Loneliness," written by David Gerrold and starring Shelly Duvall, and "A Matter of Minutes," based on Sturgeon's story "Yesterday Was Monday" and written by Harlan Ellison® and Rockne S. O'Bannon. In 2005, a play based on his story, "A Graveyard Reader," ran as part of the Theater Phantastique at the Wooden-O Theater in Los Angeles. In 2008, a short film of the story "The Other Celia," directed by Jon Knautz, aired on the Canadian Broadcasting Company.

Sturgeon wrote two books under pseudonyms, an Ellery Queen novel entitled The Player on the Other Side, and I, Libertine, under the name Frederick R. Ewing. The latter began as a joke with his friend Jean Shepherd, the popular New York radio host. Shepherd announced the publication of a non-existent book with this title, and encouraged readers to look for it in bookstores. It received so many requests that Ian and Betty Ballantine of Ballantine Books suggested that Sturgeon actually write the book, which he did, it is said, in three days.

Sturgeon was married first to his high-school sweetheart, Dorothy Fillingame, who changed her first name to "Dorothé" so that it reflected "Theodore." They had two daughters, Patricia and Cynthia. They divorced in the late 1940s. Sturgeon was married for a year to Mary Mair, a singer and poet, but the marriage was troubled from the beginning and was annulled. In 1951, Sturgeon married Marion McGahan, and remained married to her for the rest of his life, despite their separation in the mid-1960s. With Marion, he had four children, sons Robin (named after the main character in his story "Maturity") and Timothy, and daughters Tandy (named after a beloved Sherwood Anderson story) and Noël. In 1969, Sturgeon met and began to live with journalist Wina Golden, who took the last name Sturgeon and continued to use it professionally. They had a son, Andros. Wina and Ted's relationship ended in 1974, and in 1976, Sturgeon met and began to live with Jayne Tannehill Englehart (now Williams), with whom he remained until his death.

Sturgeon died at 67 in 1985 of diffuse interstitial pneumonitis. His condition was idiopathic; that is, the doctors were unable to determine the exact cause, usually exposure to asbestos. Sturgeon theorized that he had been possibly exposed from his years in the Merchant Marine (whose ships' interiors were lined with asbestos), or from living in so many basement apartments, but his preferred culprit was his favorite Zippo butane lighter, which pulled the lighter-fluid fumes down through a tiny asbestos filter into the pipe, and thus the lungs. On his death, obituaries in The New York Times, Locus Magazine, and many other outlets recognized his stature as a writer and his influence on the counterculture of the 1960s.