Adelina Ethel Dematti de Alaye (June 5, 1927 – May 24, 2016) was an Argentine human rights activist who co-founded the Mothers of the Plaza de Mayo, an organization of mothers whose children disappeared during the Dirty War of the 1970s and early 1980s. She became known as "la madre fotógrafa," or "the mother photographer," for her documentation of the Argentine dictatorship and the Mothers of the Plaza de Mayo through her photography. Her collection was later declared a "Memory of the World" by UNESCO. In addition to her work with the Mothers of the Plaza de Mayo, Dematti was also active within the Permanent Assembly for Human Rights (APDH).