Mildred Miller Posvar (b. 1924) is an internationally renowned operatic mezzo-soprano. In 1950 she married Wesley Posvar, who would go on to be the fifteenth chancellor of the University of Pittsburgh from 1967 to 1991. She founded the Opera Theater of Pittsburgh in 1978. 

The Mildred Miller Posvar Papers are arranged into seven series. The single largest portion of the collection is the audio recordings. These recordings were on cassette tapes, reel to reel, and vinyl records. Since the donation, they have been transferred to compact discs. Other items in the collection include photographs, programs, newspaper clippings, scrapbooks, and a small amount of correspondence. The majority of the materials focus on her performing career, however there are some items that relate to her position as the University’s First Lady and her involvement in the Opera Theater of Pittsburgh.