John Rut (fl. 1512 – 1528) was an English mariner, born in Essex, who was chosen by Henry VIII to command an expedition to North America in search of the Northwest Passage. On 10 June 1527 he set sail from Plymouth with two ships, Samson and Mary Guilford. The voyage was arranged by Cardinal Wolsey at the wishes of Robert Thorne, a Bristol merchant. Samson was commanded by Master Grube and Mary Guilford was commanded by Rut.
During the voyage across the Atlantic Ocean, the ships separated during a storm, and it is assumed that Samson was lost. In early July Mary Guilford met heavy ice and turned southward; they reached the Labrador coast near St. Lewis Inlet, which they explored. In late July Mary Guilford set sail for St. John's. They entered St.