Mary Ashley (1931 – June 15, 1996) was an important early video artist and performance artist, painter, and a founding member of the influential ONCE Group, together with her then-husband, the composer Robert Ashley. She was later active in the Correspondence Art scene, collaborating with Fluxus artists including Dick Higgins and George Brecht. She is credited with introducing the Ozalid process, an ammonia-based technique for the reproduction of industrial drawings, to the art world.