Chad of Mercia (died March 2, 672) was a monk and priest in 7th century England. He is considered a saint in the Roman Catholic and Anglican churches. Most of our knowledge of Chad comes from the writings of the Venerable Bede. The feast day of St. Chad is celebrated on the 2nd of March.

Shortly after the Synod of Whitby in 663/4, St. Chad was invited to become Bishop of York by King Oswiu of Northumbria after the first choice for the position, St. Wilfred, failed to return from France, where he had gone in order to be consecrated to the position. In 666 Wilfred returned from France freshly consecrated as Bishop of York, only to find Chad already occupying the same position. In 669 the Archbishop of Canterbury persuaded Chad to step down and allow Wilfred to take over - in exchange for stepping down gracefully and for his famous humility (he refused to ride a horse, preferring to walk as Jesus had), he was appointed as Bishop of Lichfield soon after.

Due to the somewhat confused nature of Chad's appointment and the continued references to 'chads' – small pieces of ballot papers punched out by voters using voting machines – in the 2000 US Presidential Election it has been jocularly suggested that St Chad is the patron saint of botched elections. This is not the case: in fact there is no patron saint of elections.

Another form of his name that survives in Modern English is St Cedd. His Anglo-Saxon name was Ceadda (pronounced "chadda").

St. Chad gives his name to many churches around the Birmingham area including its Roman Catholic cathedral, as well as St Chad's College at the University of Durham.