Arnulf (variants include Arnold, Arnoul, Arnoulf), a Germanic name common in the Middle Ages and rare at present, may refer to:
- Arnulf of Metz, saint (582–640)
- Arnulf of Eynesbury, saint
- Arnulf of Carinthia (850–899)
- Arnulf I of Bavaria (died 937) (ruled 907–927)
- Arnulf I of Flanders (ruled 918–965)
- Arnulf, Count of Holland (950-993)
- Arnulf II, Count of Flanders (960/961–987)
- Arnulf, Archbishop of Reims (died 1021)
- Arnulf of Soissons (died 1087), saint
- Arnulf of Lisieux (died 1184)
- Arnulf of Chocques (died 1118), Latin Patriarch of Jerusalem
- Arnulf of Montgomery, Anglo-Norman aristocrat