Attended McGill University, Montreal, Quebec from 1989 to 1993 and graduated with a degree in English.
In late 1999, she was going to replace actress Paula Marshall who was leaving the series Snoops (1999). However, that show was cancelled before Gilsig was set to join the cast and producer David E. Kelley gave her a role on his next show Boston Public (2000) instead.
Provided/painted all the art pieces of Patricia Clarkson's character in "The Station Agent", written and directed by her Boston Public (2000) co-star Tom McCarthy.
Her husband, Robert Salomon was her prom date in high school.
Is Jewish on her father's side and married in a traditional Jewish wedding.
Daughter of Toby Gilsig, an engineer, and wife Clare, a writer and translator.
Speaks fluent (Québécois) French.
Began her acting career at age 12 doing voice-over work.
Her name is a Gaelic variation of "Jocelyn.".
Gave birth to her 1st child at age 34, a daughter named Penelope Salomon on September 26, 2006. Child's father is her now ex-husband, Robert Salomon.
Became an American citizen in 2013.