James Thomas Fallon is an American comedian, actor, musician, and Grammy nominee best known for his work on Saturday Night Live.

Fallon was born in Brooklyn, New York, to Jim and Gloria Fallon. Fallon attended St. Mary of the Snow, a Roman Catholic parochial school, and Saugerties High School. He graduated in 1992 and attended the The College of Saint Rose in Albany, New York. Fallon majored in Computer Science, dropping out 15 credits shy of a degree.

Fallon came to fame on SNL, starting out as a featured player in the 1998-1999 season and eventually elevating himself to part of the repertoire, even becoming a co-anchor of "Weekend Update" with Tina Fey. He was most recognized for his song parodies, which he performed when Colin Quinn was doing Update and continued to showcase on special occasions after he had replaced him.

His drawback on the show was that he could rarely make it through a skit without laughing, also called corpsing. Jimmy Fallon was named one of People's 50 Most Beautiful People in 2004. Fallon left SNL in 2004 by his own choice to pursue a film career.

Before Saturday Night Live, Jimmy Fallon played in The Scheme (originally entitled The Entrepreneurs). His one line in Father's Day was cut but can still be seen in the background. He has played roles in Taxi, Anything Else, Almost Famous, Fever Pitch, Band of Brothers and Doogal. His latest project from December 2006 is Factory Girl. He occasionally does stand up comedy at the Comedy Centre in New York City.

Fallon is said to be in the running as the replacement for Conan O'Brien on Late Night when O'Brien takes over The Tonight Show from Jay Leno in 2009.In 2002, Fallon released the comedy album The Bathroom Wall which was nominated for a Grammy in 2003 for Best Spoken Comedy Album.

On August 16, 2007, it was announced that Fallon is engaged to Barrymore's producing partner Nancy Juvonen.