Bayh is a surname. Notable people with the name include:
- Birch Bayh (coach) (Birch Evans Bayh Sr., 1893–1971), American basketball and baseball coach
- Birch Bayh (Birch Evans Bayh Jr., 1928–2019) U.S. Senator from Indiana; son of Coach Birch and father of Evan
- Evan Bayh (Birch Evans Bayh III, born 1955) U.S. Senator and governor of Indiana; son of Senator Birch
- Marvella Bayh (1933–1979), wife of Senator Birch
- Susan Bayh (1959–2021), wife of Evan