Sir Bevil Grenville (23 March 1594/5 – 5 July 1643) lord of the manors of Bideford in Devon and of Stowe in the parish of Kilkhampton, Cornwall, was a Royalist commander in the Civil War who was killed in action in heroic circumstances at the Battle of Lansdowne in 1643. He served as a Member of Parliament for the county of Cornwall 1621–1625 and 1640–1642, and for the borough of Launceston in Cornwall, 1625–1629 and 1640.
Grenville was born near Withiel, west of Bodmin, Cornwall, the son of Sir Bernard Grenville (1567–1636) of Bideford in Devon and Stowe in the parish of Kilkhampton in Cornwall, by his wife Elizabeth Bevil, daughter and heiress of Philip Bevil and niece and heiress of Sir William Bevil. He was a grandson of Sir Richard Grenville (1542–1591), the heroic Elizabethan naval captain, explorer, and soldier. The Grenville family had for centuries been lords of the manors of Stowe in the parish of Kilkhampton in Cornwall, and of Bideford in Devon.
He was educated at Exeter College, Oxford.