Mary Hilde Ruth Bauermeister (born 7 September 1934) is a German artist.
Mary Bauermeister was born in Frankfurt am Main to Wolf Bauermeister, a professor of genetics and anthropology, and Laura Bauermeister, a singer.
Mary Bauermeister was artistically influenced in secondary school (1946–54) by her drawing teacher, Günter Ott. She studied in 1954–55 at the Hochschule für Gestaltung in Ulm and in 1955–56 at the Staatlichen Schule für Kunst und Handwerk in Saarbrücken. She has been active since 1957 as a freelance artist in Cologne.
In 1960, in her studio at Lintgasse 28 in Cologne, she launched a series of gatherings of members of the evolving global artistic movement Fluxus. At her invitation, avant-garde poets, composers and visual artists such as Hans G Helms, David Tudor, John Cage, Christo, Wolf Vostell, George Brecht, and Nam June Paik organised unconventional concerts of the "newest music", readings, exhibits, and actions. These activities have been described as "comparatively non-hierarchical exchanges of information across national, disciplinary and age boundaries", contributing in that way to the character of the Fluxus movement which had been developing during the 1950s.
In 1961, she took part in 's composition course at the Internationalen Ferienkursen für Neue Musik in Darmstadt. Later that same year she collaborated with Stockhausen in a theatre piece titled Originale (Originals), which was given twelve performances at the Theater am Dom, Cologne, from 26 October to 6 November 1961. Amongst the performers were Bauermeister herself (as The Painter), Nam June Paik (Actions), David Tudor (Piano and Percussion), and Hans G. Helms (The Poet). In 1962 she had her first solo exhibition at the Stedelijk Museum in Amsterdam with a simultaneous day-long performance of electronic music under Stockhausen's direction. On 3 April 1967, in San Francisco, she married Stockhausen, with whom she had two children: Julika (born 22 January 1966) and Simon (born 5 June 1967). They were divorced in 1972. She has two younger daughters, Sophie (born July 1972, father David Johnson) and Esther (born 1974, father Josef Halevi).