Mr. Lyons wrote lengthy, analytical theatre reviews for the right-leaning literary journal The New Criterion and then the financial daily The Wall Street Journal, where he served for five years in the mid-90s. In 1998, he left the Journal to become the chief theatre critic at the New York Post, supplanting the long-serving Clive Barnes. His hiring was part of a larger shake-up in the Post's theatre pages that also saw the arrival of theatre columnist Michael Riedel. During this time, he continued to contribute essays to The New Criterion, covering everything from literature to film to drama. The writer's tenure at the Post was interrupted one year in when he suffered a stroke in December 1999. When he returned to work, he took up Off-Broadway duties, and Barnes assumed his former post as first-stringer. He retired in 2004 when Frank Scheck was brought in to cover Off-Broadway.

During this period, Mr. Lyons was a frequent guest on "Theatre Talk," the PBS show hosted by Riedel. The critic's slumping, rumpled figure betrayed nothing that would hint at Mr. Lyons' previous life as a member of artist Andy Warhol's circle at the fabled Factory in Chelsea. He, in fact, had roles in two of Warhol's highly eccentric, experiment films, "Space" (1965) and, more famously, "Chelsea Girls" (1966), and contributed articles to the Warhol-founded magazine Interview. Patti Smith, in her memoir, "Just Kids," credited Lyons with inspiring her to become a musician after the two visited the famed Max's Kansas City, a Factory haunt, to hear the Velvet Underground.

Donald Lyons graduated Fordham University, and then Harvard, where he was a student in the classics department. He later taught English literature at Harvard, NYU and Rutgers. He was the author of the 1994 volume, "Independent Visions: A Critical Introduction to Recent Independent American Film."