Michael Witzel (born 1943) is a German-American philologist, a professor of Sanskrit at Harvard University, United States.

Witzel was born at Schwiebus, then in Germany, now Poland.

He studied Indology in Germany (from 1965 to 1971) under Paul Thieme, H.-P. Schmidt, K. Hoffmann and J. Narten as well as in Nepal (1972–1973) under the Mīmāmsaka Jununath Pandit. At Kathmandu (1972–1978), he led the Nepal-German Manuscript Preservation Project and the Nepal Research Centre. He has taught at Tübingen (1972), Leiden (1978–1986), and at Harvard (since 1986) and has held visiting appointments at Kyoto (twice), Paris (twice), and Tokyo (twice). He has been teaching Sanskrit since 1972.

He is noted for his studies of the dialects of Vedic Sanskrit, old Indian history, the development of Vedic religion, and the linguistic prehistory of South Asia. He is editor-in-chief of the Electronic Journal of Vedic Studies (EJVS) and the Harvard Oriental Series. He has been president of the Association for the Study of Language in Prehistory (ASLIP) since 1999, as well as of the new International Association for Comparative Mythology (2006-). He was elected into the American Academy of Arts and Sciences in 2003, and was elected as an honorary member of the German Oriental Society (DMG) in 2009.