Sir William Chester (1509 – c. 1574) was one of the leading English Merchants of the Staple and Merchant Adventurers of the mid-16th century, five times Master of the Worshipful Company of Drapers (and twice more for part-years), Lord Mayor of London in the year 1560–61 and Member of Parliament for the City of London. He should not be confused with his contemporary, William Chester, merchant of Bristol, M.P.