James O'Halloran, KC (c.1820 – June 1, 1913) was a Quebec lawyer and political figure. He was born about 1820 (some sources say 1821) near Fermoy, County Cork, Ireland and came to Canada with his family in 1828. He studied at the University of Vermont and served in the U.S. Army during the war with Mexico. He returned to Lower Canada in 1849, was admitted to the bar in 1852 and set up practice in Cowansville. He was elected to the Legislative Assembly of the Province of Canada for Missisquoi as a member of the parti rouge; he was reelected in 1863. He opposed Confederation. O'Halloran was named Queen's Counsel on February 12, 1864.