Marie "Maja" Flagstad (née Johnsrud) (November 15, 1871[1] – January 18, 1958) was a Norwegian pianist, choral conductor, and répétiteur.
At the opening of the cabaret theater Chat Noir, she accompanied Bokken Lasson singing "Tuppen og Lillemor" (the Norwegian version of "I Don't Want to Play in Your Yard") on March 1, 1912.
The Flagstad family was central in the short-lived Opera Comique (1918–1921), where Kirsten also sang.
She was a guest conductor at the National Theater in Bergen and was credited with discovering the performing artist and bass singer Bjarne Bø during a performance at Bergen Cathedral in 1929.
She worked extensively as a répétiteur, accompanying well-known artists such as Hauk Aabel and Erik Ole Bye.