Michael O'Connor (4 October 1829 – 14 February 1883) was the first Catholic Bishop of Ballarat, located in Victoria, Australia.
O'Connor was born in Dublin, Ireland and educated at Maynooth and was a Dunboyne Scholarship Student; at Maynooth, he won numerous honours. Taking holy orders, he was appointed parish priest of Rathfarnham, Dublin. In 1875, he was appointed first Catholic Bishop of Ballarat in Victoria, being installed in the cathedral of that city by Archbishop Goold on 20 November. O'Connor died on 14 February 1883.