William Bonville, 1st Baron Bonville (12 or 31 August 1392 – 18 February 1461), was an English nobleman and an important, powerful landowner in south-west England during the Late Middle Ages. Bonville's father died before Bonville reached adulthood. As a result, he grew up in the household of his grandfather and namesake, who was a prominent member of the Devon gentry. Both Bonville's father and grandfather had been successful in politics and land acquisition, and when Bonville came of age, he gained control of a large estate. He augmented this further by a series of lawsuits against his stepfather, Richard Stucley. Bonville undertook royal service, which then meant fighting in France in the later years of the Hundred Years' War. In 1415, he joined the English invasion of France in the retinue of Thomas, Duke of Clarence, Henry V's brother, and fought in the Agincourt campaign. Throughout his life, Bonville was despatched on further operations in France, but increasingly events in the south-west of England took up more of his time and energy, as he became involved in a feud with his powerful neighbour Thomas Courtenay, Earl of Devon.