Israel Horovitz was born in Wakefield, Massachusetts, in 1939. He wrote his first play at age 17.

In the years that followed nearly 50 Horovitz plays have been translated and performed in as many as 30 languages worldwide. Horovitz is America's most-produced playwright in France. In French theatre history, no other American has had more plays translated and produced in the French language. As a director, Horovitz has created world premiere productions of many of his plays including the French premiere of Line. As an actor, Horovitz has appeared not only in his own plays, but also on film and television in the US, France and England.

Among the best known Horovitz early plays are: The Indian Wants The Bronx, which introduced Al Pacino and John Cazale to the American stage: Line, which introduced Richard Dryfuss; It's Called The Sugar Plum, which introduced Marsha Mason and subsequently Jill Clayburgh; Rats, which introduced Scott Glen and The Primary English Class, which starred Diane Keaton in its New York premiere.

Horovitz has premiered a number of his plays at the Gloucester Stage Company which he founded around 1980 in his adopted town of Gloucester, Massachusetts. Some of his more recent work was created as a cycle of Massachusetts-based plays. Of these Park Your Car In Harvard Yard enjoyed a particularly successful run on Broadway starring Jason Robards and Judith Ivey. Other titles in the cycle include Henry Lumper, Fighting Over Beverley, Unexpected Tenderness, Barking Sharks, North Shore Fish (the Showtime film of which features a cameo performance of the author) and The Widow's Blind Date (for which Mr. Horovitz has completed a screenplay to also direct).

Horovitz has written a number of screenplays including the prize-winning The Strawberry Statement, Believe In Me, Author! Author! (which starred Al Pacino) and A Man In Love and many more. He is currently writing for Warner Brothers with screenplays including James Dean (a bio-pic recently broadcast on TNT), With Honors and a remake of A Star Is Born.

Horovitz has won numerous awards including the OBIE (twice), the EMMY, Prix du Plaisir de Theatre (for Line in Paris), Prix du Jury (Cannes Film Festival), the NY Drama Desk Award, an Award in Literature of the American Academy of Arts and Letters, the Eliot Norton Prize and many others. Horovitz founded the New York Playwrights Lab.

He is married to Gillian Adams (a British National Marathon champion) and is the father of 5 children including Beastie Boys member Adam Horovitz .