Martha Wainwright (born May 8, 1976 in Montreal, Quebec, Canada) is a Canadian-American folk-pop singer.
Martha McGarrigle? Wainwright is the daughter of Loudon Wainwright III and Kate McGarrigle?, and the sister of Rufus Wainwright. She has frequently appeared on recordings by her family members, and has released several independent EPs. Her full length self-titled debut was released in 2005 by Drowned In Sound, and debuted at number 18 on the Canadian album sales charts.
Her band also includes her cousin Lily Lanken, the daughter of her mother's sister (and collaborator) Anna McGarrigle?. Wainwright frequently tours and records with family friend Teddy Thompson.
She performed with Irish/Scottish band Snow Patrol's singer Gary Lightbody for the 2006 Snow Patrol album "Eyes Open".