Henry O'Leary (May 13, 1832 – November 7, 1897) was an Irish-born businessman and political figure in New Brunswick, Canada.
He was born in Castledown in County Cork, the son of Theophilus O'Leary and Ellen Power.
In 1864, he purchased land nearby where he built a canning plant for lobster and salmon.
O'Leary acquired additional canneries until he had at least 30 in New Brunswick and several in Prince Edward Island.
He was first elected to the provincial assembly in an 1873 by-election held after the death of William Shand Caie.