Martha Wainwright (born May 8, 1976) is a Canadian-American folk-rock singer-songwriter.She is signed with the independent record labels Rounder Records in the United States, DiS in the United Kingdom, MapleMusic Recordings in Canada, V2 Records in Europe and Shock Records in Australia. She has received positive reviews for her performances. In 2013, she recorded the soundtrack album for the fourth season of the television drama series Trauma,

She participated in the 2015 edition of Canada Reads, advocating for Jocelyne Saucier's novel And the Birds Rained Down.

She is the daughter of American folk singer and actor Loudon Wainwright III and Canadian folk singer-songwriter Kate McGarrigle. She was raised in a musical family along with her older brother, Rufus Wainwright, in Montreal, Quebec, Canada.