James O'Brien (1806-1882) was a nineteenth-century Irish barrister, politician and judge. He was born in Granard, County Longford, a younger son of James O'Brien and Margaret Long. He went to school in Dublin, and entered the University of Dublin, where he graduated BA in 1829 with a gold medal in science. He entered Gray's Inn in 1831 and was called to the Irish Bar in 1831, Queen's Counsel in 1841.