- Marcia Feuerstein Architectural Collection, 1982/19961
- Margaret (Peggy) Cochrane Architectural Collection, 1951/19901
- Maria Peeva Architectural Collection, 1978/20061
- Maria von der Weppen Architectural Collection, 1978/20011
- Marie-Louise Laleyan Architectural Collection, 1961/20071
- Mary Brown Channel Architectural Collection, 1936/2002, bulk 1936/19501
- Mary Lou Drosten Architectural Collection1
- Meeting Minutes of the Art League of Philadelphia and Diary of Art League Member Elsa Marie Hofheinz, 1928/19471
- Milka Bliznakov Prize Records, 1999/20191
- Milka T. Bliznakov Papers and Architectural Drawings, 1946/20101