Sinis may refer to:
Places Sinis peninsula in western Sardinia, forming the northern cape of the Bay of Oristano Titular see of Sinis, Catholic diocese Sinis, now called Sinno, a river in southern Italy
Other Sinis (mythology), also known as Pityokamptes, a bandit killed by Theseus in Greek mythology Sinis, the name of a powerful Shade in the Myth (computer game series) slain by Alric in single combat