Nausitheus (see also Nausinoüs) was the helmsman of Theseus' ship when he set sail for Crete to kill the Minotaur. (Some accounts, however, say Phereclus was the helmsman.)

His name literally means 'sailor god', from nautes, 'sailor' and theus (Doric form of theos), 'god'. Perhaps, since Theseus was the son of Poseidon, the sea god, we should interpret the name more precisely as 'sailor in the service of the sea god'.