Robert Barnes (1495 – 30 July 1540) was an English reformer and martyr.
Barnes was born in King's Lynn, Norfolk in 1495, and was educated at Cambridge, where he was an Augustinian priest of the Austin Friars. Sometime after 1514 he was sent to study in Leuven. Barnes returned to Cambridge in the early 1520s, where he graduated Doctor of Divinity in 1523, and, soon after, was made Prior of his Cambridge convent.
John Foxe says that Barnes was one of the Cambridge men who gathered at the White Horse Tavern for Bible-reading and theological discussion in the early 1530s. At the encouragement of Thomas Bilney, Barnes preached at the Christmas Day Midnight Mass in 1525 at St Edward's Church in Cambridge. Barnes' sermon, although against clerical pomp and ecclesiastical abuses, was neither particularly unorthodox nor surprising. However, after seeing a churchwarden whose civil suit resulted in the imprisonment of a local man, Fr. Barnes departed from his prepared text to den