Look up Martinus in Wiktionary, the free dictionary.
Martinus may refer to:
- Martin (magister militum per Armeniam), 6th-century Byzantine/East Roman general
- Martinus (son of Heraclius), 7th-century Byzantine/East Roman co-emperor
- Martinus of Arles, doctor of theology, priest, and author on demonology and witches
- Saint Martinus or Saint Martin of Tours
- Martinus College, a secondary school in the Netherlands
- VV Martinus, a Dutch volleyball club