Henry O'Brien (1793 – 27 January 1866) was an Irish-born politician and pastoralist in New South Wales, Australia.
He was born at Hollymount in County Mayo to farmer Henry O'Brien and Catherine née Browne.
His father died when he was young and he and his brothers Cornelius and Thomas were raised by their uncle William Browne.
O'Brien remarried on 28 November 1840 to Elizabeth Sadlier Cruden, with whom he had a son also named Henry.
[1][4] O'Brien was winding up his affairs in New South Wales, intending to join Elizabeth in England, however he died at Douro near Jugiong on the Yass Plains in 1866 (aged 73).