Crimthann, Cremthann or in Modern Irish Criofan, is a masculine Irish given name meaning fox. Notable people with the name include:

• Crimthann mac Fidaig, legendary High King of Ireland of the 4th century AD
• Crimthann Nia Náir, legendary High King of Ireland of the 1st century AD
• Crimthann Coscrach, legendary High King of Ireland of the 3rd century BC
• Crimthann mac Énnai, 5th century AD King of Leinster
• Crimthann mac Áedo, 7th century AD King of Leinster
• Crimthann Srem mac Echado, 6th century AD King of Munster