Chelsea, city (1990 pop. 28,710), Suffolk co., E Mass., an industrial suburb of Boston; settled 1624, inc. as a town 1739, as a city 1857. It has made printed goods, rubber, plastics, electrical machinery, shoes, and paint. Oil storage tanks line Chelsea Creek and the Mystic River. At the battle of Chelsea Creek (1775), Revolutionary forces made one of their first captures of a British ship. During the siege of Boston (1775–76), part of Washington's army was stationed here. In recent decades Chelsea has suffered from major fires, job loss, and municipal corruption.