Gilroy was born in Manhattan, New York, the son of Ruth Dorothy (née Gaydos), a Sculptor and Writer, and Frank D. Gilroy, an award-winning Playwright, Director, and movie Producer, who received the Tony Award for Best Play and the Pulitzer Prize for Drama for his play The Subject Was Roses in 1965. He is the brother of Screenwriter Dan Gilroy and Editor John Gilroy. Through his father, he is of Italian, Irish and German descent. He has two children, Sam and Kathryn, and is married to Susan Gilroy.
Gilroy was raised in Washingtonville, New York. He graduated from Washingtonville High School in 1974 at 16 years old and attended Boston University for two years before dropping out to concentrate on his music career.
Gilroy has written many scripts for film, starting with the script for The Cutting Edge in 1992. This was followed by Dolores Claiborne in 1995 and The Devil's Advocate in 1997. He was one of five credited Writers on Michael Bay's Armageddon, the highest-grossing film of 1998. Gilroy's next script was Proof of Life in 2000. In 2002, 2003 and 2007 he wrote the screenplays for The Bourne Identity, The Bourne Supremacy and The Bourne Ultimatum, and wrote and directed the next installment of the Bourne series, The Bourne Legacy (2012).
Gilroy's directorial debut was in 2007, when he directed the film Michael Clayton, which his brother John Gilroy edited. The film was nominated for seven Academy Awards, including Best Picture, Best Director and Best Actor. In addition to its Edgar Award, the film won one Oscar, for Best Supporting Actress (Tilda Swinton). The film was a box-office success, grossing over $92 million worldwide.
He also wrote and directed his next film, Duplicity, released March 20, 2009, and starring Clive Owen, Julia Roberts and Tom Wilkinson. He then took over as Director of the next entry in the Bourne series as well as co-writing; the film, The Bourne Legacy, was released August 10, 2012, starring Jeremy Renner, Rachel Weisz, Edward Norton, Joan Allen, and Albert Finney.
In September 2013, Gilroy delivered a screenwriting lecture as part of the BAFTA and BFI Screenwriters' Lecture Series.
In 2016, Gilroy co-wrote the script to the sci-fi war film Rogue One, directed by Gareth Edwards. It is a prequel to the 1977 classic Star Wars. Gilroy shared writing duties with fellow filmmaker Chris Weitz.
