Mary B. Timony (born 1970) is an American guitarist and singer. She has been a member of the bands Wild Flag, Helium, and Autoclave, and also released music under her own name. Currently she is fronting a new band EX-HEX.
Timony was born to James and Joan Timony of Washington, D.C., and raised in the neighborhoods of Glover Park and Wesley Heights. As a teenager, she attended the Duke Ellington School of the Arts in Georgetown where she played guitar in the jazz band and also studied viola.
Wild Flag was a "supergroup" teaming Timony with Carrie Brownstein and Janet Weiss of Sleater-Kinney. In music videos for Helium she earned the admiration of Beavis & Butthead (see clip for "Pat's Trick").