173 Ino is a large asteroid and the parent body of the Ino family, located in the central regions of the asteroid belt, approximately 150 kilometers in diameter. It was discovered on 1 August 1877, by French astronomer Alphonse Borrelly at Marseille Observatory in southern France, and named after the queen Ino from Greek mythology. The dark Xk-type asteroid has a rotation period of 6.15 hours.