Megan Gallagher is an American theatre and television actress, best known for Mr. & Mrs. Smith, Van Wilder: Party Liaison, and The Ambulance.

Theatre credits include her Broadway debut as Lieutenant Commander Joanne Galloway in A Few Good Men (Music Box Theatre) and Harper Pitt/Martin Heller in Angels in America: Perestroika/Millennium Approaches (Walter Kerr Theatre); Off-Broadway, as W2 in Play, Ru in Come and Go, and Elmire in Tartuffe (American Place Theatre); and regionally, as Nancy in 63 Trillion (Odyssey Theatre), Margaret in Cat on a Hot Tin Roof (Arena Stage), and Liz Essendine in Present Laughter (Williamstown Theatre).