Marianus
Marianus is a male name, formerly an Ancient Roman family name, derived from Marius. Marianus may refer to:
- Marianus of Auxerre, French monk and saint
- Marianus Scotus of Mainz, otherwise Máel Brigte, Irish monk and chronicler
- Marianus Scotus of Regensburg, Irish monk, abbot of St. Peter's at Regensburg
- Marianus II of Cagliari, also known as Torchitorio II, Judge of Cagliari from c. 1102 to his death
- Marianus of Florence, Friar Minor, historian, and chronicler of the Franciscan Order
- Marianus Brockie, D.D., Benedictine monk
- Jozef Marianus Punt, Roman Catholic bishop of Haarlem-Amsterdam in the Netherlands
;Marianus of Arborea:
- Marianus I of Arborea, the Judge of Arborea from 1060 to his death
- Marianus II of Arborea, the Judge of Arborea from 1241 to his death
- Marianus III of Arborea, the sole Judge of Arborea from 1308 to his death
- Marianus IV of Arborea, called the Great, the Judge of Arborea from 1347 to his death
- Marianus V of Arborea, the Judge of Arborea from 1387 until his death
;Marianus of Torres:
- Marianus I of Torres, the Judge of Logudoro from 1073 until c. 1082
- Marianus II of Torres, the Judge of Logudoro from 1218 until his death
