British seaman whose visit to Moscow in 1553–54 laid the foundations for English trade with Russia.

In 1553 Chancellor was appointed pilot general of Sir Hugh Willoughby's expedition in search of a northeast passage from England to China. The three-vessel fleet was to rendezvous at Vardø, Nor., but because of stormy weather Chancellor's was the only ship to make it to Vardø. Willoughby and his crew died in Lapland, but Chancellor continued on into the White Sea, then journeyed overland to Moscow. There Tsar Ivan IV greeted him with warm hospitality and gave him a letter granting the English favourable conditions for trade with Russia. Chancellor rejoined his ship in the summer of 1554 and returned to England. His successful negotiations with the tsar resulted in the formation (1555) of the Muscovy Company, which was given a monopoly of Russian trade.

From October 1555 to July 1556 Chancellor was again in Moscow on a trading mission, but on the return voyage he lost his life in a shipwreck off the coast of Scotland.