Rebecca L. Cann (born 1951) is a geneticist who made a scientific breakthrough on mitochondrial DNA variation and evolution in humans, popularly called Mitochondrial Eve. Her discovery that all living humans are genetically descended from a single African mother who lived <200,000 years ago became the foundation of the Out of Africa theory, the most widely accepted explanation of the origin of all modern humans. She is currently Professor in the Department of Cell and Molecular Biology at the University of Hawaiʻi at Mānoa.