LeBlanc is married to Melissa McKnight, and the couple has a daughter, Marina Pearl LeBlanc, born February 8, 2004. Marina suffers from the rare brain disorder, cortical dysplasia. LeBlanc is a stepfather to Tyler and Jacqueline from McKnight's marriage to musician Anthony Esposito. In August 2005, LeBlanc apologized to his wife and the public for having inappropriate contact with an overly aggressive stripper during a vacation in British Columbia. The couple separated January 1, 2006, and in March of that year, LeBlanc filed for divorce from his wife McKnight of 3 years, citing irreconcilable differences. According to ET, LeBlanc has recently been dating co-star of "Joey" Andrea Anders.

Before breaking into an acting career, LeBlanc worked as a photography model. His photo appeared on the cover of the 1991 issue of the Spartacus International Gay Guide (although this photo was apparently sold by a modeling agency).

"LeBlanc" is French for "The White." His father's name is Paul LeBlanc, and his mother name is Pat Grossman. He is of mixed Irish, Dutch, English, and French ancestry on his father's side, and of Italian ancestry on his mother's. He has one younger half-brother, Justin LeBlanc.

In addition to his well-known television roles, LeBlanc has also appeared in some well-known Hollywood films including Lost in Space, Charlie's Angels, and Charlie's Angels: Full Throttle.

He also appeared as the boyfriend of Kelly Bundy in Married... with Children in the early 1990s (and starred in that sitcom's short-lived spinoff, Top of the Heap). In the fall of 2004, after the finale of Friends in May of that year, LeBlanc's spinoff, Joey, debuted. However, the show never became a hit, and there has been speculation that the show will be canceled after its second season on air.

He has also starred in several lesser or less successful films including The Killing Box (1993), Ed (1996), Lookin' Italian (1998), and All the Queen's Men (1999).