He was the younger son of Nicholas Osborne (died 25 December 1714) and wife Anne née Parsons, and grandson of Sir Thomas Osborne, 5th Baronet and Sir Laurence Parsons, 1st Baronet.
He succeeded his brother, Sir Nicholas Osborne, 6th Baronet, in 1719.
[1] Educated at the Middle Temple, he practised as a barrister after being called to the Bar at King's Inns, Dublin in 1726.
Sir John served as member of Parliament in the Irish House of Commons for Lismore from 1719 until 1727 and for County Waterford between 1727 and 1743.
Sir William Osborne, 8th Baronet, who succeeded his father in the baronetcy in 1743.