Mary Butler Lewis (1903–1970)[1] was an American archaeologist, anthropologist, and public educator best known for her contributions to the fields of Mesoamerican archaeology and Northeastern and Central U.S. prehistory.[2] She was the first female archaeologist to earn a doctorate degree from the department of anthropology at the University of Pennsylvania, as well as one of the first female archaeologists to earn a Ph.D. in the United States.[3][1] She worked with the University of Pennsylvania Museum as the assistant of the American section and as a research assistant, where she conducted her own fieldwork in Piedras Negras in Guatemala.[4] She pioneered research on Mesoamerican pottery and ceramics, which paved the way for many new projects.[3][2] President of the Philadelphia Anthropological Society, Butler conducted historical research in Pennsylvania and New York.[5]