Beauchamp Bagenal Harvey (died 28 June 1798) was a barrister and a commander of the United Irishmen in the Battle of New Ross during the 1798 Rebellion. He was the eldest son of Francis Harvey of Bargy Castle, Wexford, who was one of the six Clerks in Chancery. Bagenal was educated at Trinity College, Dublin. He was a Protestant who was known for his liberal principles and as a supporter of Catholic emancipation. From June 1792 he was a member of the Dublin Society of United Irishmen, founded by James Napper Tandy and Archibald Hamilton Rowan.