This timeline is based on various published articles and interviews, and owes a lot in particular to the writings of Don Shewey and W.D. King, but the text is my own except where indicated.
1943: Born November 12, New York City, to William Shawn (1907-1992) and Cecille Lyon Shawn. Both parents were journalists who worked at The New Yorker together, where William Shawn was editor-in-chief from 1952 to 1987. His father's name was originally Chon; William changed it in the 1930s to avoid being mistaken for Chinese.
1960s: Attends Harvard, where his roommate is Jonathan Schell, who later writes The Fate of the Earth for The New Yorker. Graduates with B.A. in History.
1965: Goes to India on a Fulbright Fellowship, teaching English.
1966-68: Studies philosophy and economics at Oxford. Writes first play, Four Meals in May, of which he later says "I thought it was the answer to the war in Vietnam. I thought they would rename the country after me when people saw that play!" [Shewey] Returns to New York and teaches English, Latin, and drama.
1970: Writes The Hotel Play while staying in a hotel in the West Indies. Returning to New York that year, he sees Andre Gregory's adaptation of Alice in Wonderland and meets Gregory and another future frequent collaborator, Larry Pine.
1971: Reading of The Hospital Play at the Public Theater, prompting critic Martin Esslin to say "I will stake my career on the failure of this play!" [King] (Esslin's bet was a sound one.)
1975: Our Late Night, first produced play and first collaboration with director Andre Gregory. Wins Obie Award. Shawn works at a copy shop. Writes A Thought in Three Parts on commission for the Public Theater.
1977: Commissioned to translate Machiavelli's The Mandrake for the Public Theater, ends up making his acting debut in it as well. His brother Allen Shawn composes the score.
1978: Conceives the idea of My Dinner with Andre with Gregory and begins recording conversations that will eventually become the script.
1979: First film role, in Woody Allen's Manhattan.
Meets long-time companion Deborah Eisenberg at some point in the 1970s.
1981: The Hotel Play finally produced at La MaMa ETC, with cast including Shawn and Eisenberg.
1982: First TV role: two appearances on Taxi.
1985: Aunt Dan and Lemon wins Obie Award for Distinguished Playwriting.
1990: Travels to Guatemala, Honduras, Nicaragua, and El Salvador while writing The Fever. Performs the piece at friends' apartments in New York.
1991: The Fever opens at the Public Theater and wins Obie Award for Best New American Play.
1993: Starts longest-running and strangest TV role, as Grand Nagus Zek on Star Trek: Deep Space Nine.
2000: Reunited with Andre Gregory for brief New York production of The Designated Mourner acted by Shawn, Eisenberg, and Pine.
2004: Even more dismayed at the US political scene than usual, produces the brief anthology Final Edition in collaboration with Eisenberg, Schell, Noam Chomsky, and Mark Strand.