American theatre director and actor. 1934-1999. One of the cornerstones of theatrical improvisation in the United States, along with Viola Spolin and Paul Sills. Close, who dedicated his entire career to the art form, is often credited with bringing legitimacy to improv in the U.S.

After a stint with the St. Louis cast of the Compass Players in 1957, Close went to New York for a brief stint as a hip stand up comic. In 1961, he moved to Chicago to join the cast of Second City until 1965, when he was fired for substance abuse (Close was a heroin addict). He then moved to San Francisco, where he dropped acid with the Merry Pranksters, created light shows for the Grateful Dead, and helped organize San Francisco's counterculture satire and improv troupe, The Committee. Back to Chicago in 1970, where, in his workshops at the Kingston Mines Company Store, he developed and trained improvisers in the longform style that would become his legacy to the improv community, the Harold.

I have a grandiose idea of what free improvisation would look like. You go out in the beginning of the evening, get a series of suggestions from the audience, go on through the evening and at the end perform something like the equivalent of a play that doesn't look like a play- it's sort of like designing a 707 in flight. You're out there and you have a few simple rules to follow. The idea is that each of these improvised plays develops a form and structure that is particularly suited to the subject mattter.
From 1972-1983 Close was the resident director at Second City, where he trained comedians like John Belushi, Bill Murray, John Candy. He left to found the ImprovOlympic with Charna Halpern.

Before he died of emphysema, he wrote in his will that after death, his skull should go to the Goodman Theatre in Chicago. It was kept in a cardboard box labelled "Warning - Del's Skull - Do Not Put Anything on Top - Do Not Open" in the ImprovOlympic office before it was moved into a clear lucite basketball display box with red velvet for the presentation. At the ceremony, Artistic Director Robert Falls took the skull out of the box and held it in the classical Hamlet/Yorick pose - the photo made the front page of the Chicago Tribune.

Del Close's published work includes:
A spoken word album with John Brent, How to Speak Hip, the transcript of which still finds its way to the Web uncredited; Truth in Comedy: a Manual for Improvisation, a book written with Charna Halpern; and several issues of Wasteland (DC comics), which he co-wrote with John Ostrander.