John Maltravers, 1st Baron Maltravers (1290?–1365) was an English nobleman and soldier.
He was son of Sir John Maltravers (1266–1343?) of Lytchett Matravers, Dorset, born by his first wife Alianor, about 1290. He was knighted, as was his father, with Edward, Prince of Wales, on 12 May 1306. He is said to have been taken prisoner at the battle of Bannockburn in 1314.
On 20 October 1318 Maltravers was chosen knight of the shire for Dorset. He seems to have sided with Thomas, Earl of Lancaster against the king Edward II, and was in his early life a close associate of Roger Mortimer, 1st Earl of March. In September 1321 he received pardon for felonies committed in pursuit of the Despensers, but in the following December is described as the king's enemy. In the spring of 1322 he was in arms against the king, and attacked and burnt the town of Bridgnorth. He was present at the battle of Boroughbridge on 16 March, and after the execution of Earl Thomas went overseas.
Maltravers would appear to have come back with Mortimer and Isabella of France in October 1326, receiving restitution of his lands in 1327, with a grant out of the lands of Hugh Despenser. On 3 April he was appointed one of the keepers of the deposed king Edward II, the other being his brother-in-law Thomas de Berkeley, 3rd Baron Berkeley. Adam Murimuth says that Edward was killed by order of Maltravers and Thomas Gourney, but later scholars doubt this. Maltravers and Berkeley remained in charge of the body until its burial at Gloucester on 21 October.
During the next few years Maltravers was employed on commissions of oyer and terminer. In that of February 1329, with Oliver de Ingham and others, he was appointed to try those who had supported Henry, Earl of Lancaster, in his intended rising at Bedford. He was also on several occasions a justice in eyre for the forests, and was in 1329 made keeper of the forests south of Trent. On 4 April 1329 the pardon granted to him two years earlier was confirmed, in consideration of his services to Isabella and the king at home and abroad. In May he accompanied the young king Edward III to France; and the next year was steward of the royal household.