John Craven Westenra (31 March 1798 – 5 December 1874) was an Irish Whig politician and army officer. Born in Walsh Park, County Tipperary, Ireland, he was the son of Warner Westenra, 2nd Baron Rossmore and Mary Ann Walsh, and the brother of Henry Westenra, 3rd Baron Rossmore. He first married Eleanor Mary East née Jolliffe, daughter of William Jolliffe, in 1834. After she died in 1838, he then married Ann Daubuz, daughter of Lewis Charles Daubuz, in 1842, and they had at least one /child: Mary Anne Wilmot Westenra (died 1894).