Arttu is a male name.
Arttu is a short form of the name Artturi, which is a Finnish form of the name Artur. There is no clear origin of the name Artur. It could be derived from the Roman surname Artorius, but could be as well of Celtic, Irish or Nordic (Arnthor) origin.
Arttu means “bear” (from Celtic “artos”), “eagle” (from Old Norse “arn”) and the God “Thor” and “stone” (from Irish “art”).