Del Close was born on March 9, 1934 in Manhattan, Kansas, the son of an inattentive alcoholic father. He ran away from home at the age of 17 to work in a traveling side show, but returned to attend Kansas State University. At age 19 he performed in summer stock with the Belfry Players at Lake Geneva, Wisconsin. At age 23 he became a member of the Compass Players in St. Louis. When most of the cast—including Mike Nichols and Elaine May—moved to New York City, Close followed. He developed a stand-up comedy act, appeared in the Broadway musical revue The Nervous Set, and performed briefly with an improv company in Greenwich Village with fellow Compass alumni Mark and Barbara Gordon. Close also worked with John Brent to record the classic beatnik satire album How to Speak Hip, a parody of language-learning tools that purported to teach listeners the secret language of the “hipster”. In 1960 Del Close moved to Chicago, his home base for much of the rest of his life, to perform and direct at Second City, but was fired due to substance abuse. He spent the latter half of the 1960s in San Francisco where he was the house director of The Committee, toured with the Merry Pranksters, and created light images for Grateful Dead shows. In 1972 he returned to Chicago, and to Second City. He also directed and performed for Second City’s troupe in Toronto, in 1977. Over the next decade he coached many popular comedians. In the early 1980s he served as “house metaphysician” at Saturday Night Live; for many years, a significant percentage of the show’s cast were Close protégés. He spent the mid-to-late 1980s and 1990s teaching improv, collaborating with Charna Halpern at Yes And Productions and the ImprovOlympic Theater with Compass Players producer David Shepherd.

In 1987, Del Close mounted his first scripted show, Honor Finnegan vs. the Brain of the Galaxy, created by members of Close and Halpern’s Improv Olympics from a scenario by Close, at CrossCurrents in Chicago. Running concurrently at the same theater was “The TV Dinner Hour”, written by Richard O’Donnell of New Age Vaudeville, featuring Close’s running routine as The Rev. Thing of the First Generic Church of What’s-his-name. During this period, Close also appeared in several movies; he portrayed a corrupt alderman John O’Shay in The Untouchables, and an English teacher in Ferris Bueller’s Day Off. He also co-authored the graphic horror anthology Wasteland for DC Comics with John Ostrander, and co-wrote several installments of Grimjack’s backup feature Munden’s Bar. Close died of emphysema on March 4, 1999, at the Illinois Masonic Hospital (now the Advocate Illinois Masonic Medical Center) in Chicago, five days before his 65th birthday. In his will, he bequeathed his skull to Chicago’s Goodman Theatre, to be used in its productions of Hamlet , and specified that he be duly credited in the program as portraying Yorick. Charna Halpern, Close’s long-time professional partner and the executor of his will, donated a skull—purportedly Close’s—to the Goodman in a high-profile televised ceremony on July 1, 1999. A front-page article in the Chicago Tribune in July 2006 questioned the authenticity of the skull, citing the presence of dentition (Close was edentulous at the time of his death) and autopsy marks (Close was not autopsied), among other problems. Halpern stood by her story at the time, but admitted in a New Yorker interview three months later that she had purchased the skull from a local medical supply company. After Close’s death, his former students in the Upright Citizens Brigade founded the annual Del Close Marathon, three days of continuous improvisation by hundreds of performers at various venues in New York City.