Alonso Antonio de San Martín was a Catholic prelate who served as Bishop of Cuenca (1681–1705) and Bishop of Oviedo (1675–1681). He was an illegitimate son of King Felipe IV of Spain.
- Occupation
- Catholic priest, Catholic bishop
- Position held
- Roman Catholic Bishop of Cuenca, Roman Catholic Bishop of Oviedo
- Citizenship
- Spain
- Born
- December 12, 1642
- Died
- July 21, 1705
