I started acting in my parents living room when I was five years old.

Megan trained at the Juilliard School where her classmates in 1982 included Penny Johnson Jack Kenny Jack Stehlin and Lorraine Toussaint. Early life and education
Gallagher was born in Reading Pennsylvania and grew up in Wyomissing Pennsylvania. Her best-known roles are probably as Garry Shandling's wife on the HBO comedy The Larry Sanders Show (1992–1995) and as Catherine Black wife of Frank Black (Lance Henriksen) on the TV series Millennium (1996–1999).

Her best-known roles are probably as Garry Shandling's wife on the HBO comedy The Larry Sanders Show (1992–1995) and as Catherine Black wife of Frank Black (Lance Henriksen) on the TV series Millennium (1996–1999).