The red-haired Megan Gallagher first won attention as undercover cop Tina Russo in the waning days of "Hill Street Blues" (NBC, 1986-87). She had previously made her TV debut in the 1984 CBS miniseries "George Washington", playing a woman enchanted by the title character (Barry Bostwick). Gallagher had received her training at Juilliard under the tutelage of John Houseman, and later joined his Acting Company, touring the USA in classical repertory theater. She later appeared in plays at the Long Wharf Theatre in New Haven, CT, and appeared as Roxanne in a touring company production of "Cyrano de Bergerac". It was not until 1989 that she made her Broadway debut, playing the female lead in then-fiance Aaron Sorkin's "A Few Good Men".
In addition to "Hill Street", Gallagher's series credits include a stint as Dabney Coleman's on-again, off-again girlfriend on "The Slap Maxwell Story" (ABC, 1987-88) and Wayloo Marie, the broadcasting queen of "China Beach" (ABC, 1988-89). She had a recurring role as the wife of Bruce Greenwood's "Nowhere Man" (UPN, 1995-96) before landing the female lead in Chris Carter's "Millennium" (Fox, 1996- ). In longforms, Gallagher was a woman who runs a mobile camp for the blind and helps save Jeremy London from delinquency in "Breaking Free" (Disney Channel, 1995) and co-starred in "Abducted: A Father's Love" (NBC, 1996). Gallagher's feature film work has been limited. She co-starred opposite Eric Roberts in "The Ambulance" (1990), although the film went straight to video and was Costas Mandylor's girlfriend in "Crosscut" (1995).