Baldwin I may refer to:
- Baldwin I of Flanders (died 879)
- Baldwin I, Count of Hainaut and shortly Count of Flanders ( 1030–1070)
- Baldwin I of Jerusalem (1060–1118)
- Baldwin I of Ramla (died 1138)
- Baldwin I of Constantinople (1172–1205)
See also
- Baudouin of Belgium (1930–1993)