Isaac Sears (1 July 1730 – 28 October 1786) was an American merchant, sailor, Freemason, and political figure who played an important role in the American Revolution.
He was born July 1, 1730 at West Brewster, Massachusetts the son of Joshua and Mary Sears. He was a descendant of Richard Sears, who emigrated to the colonies from Colchester, England, in 1630. While he was a child the family moved to Norwalk, Connecticut.
At the age of sixteen he was apprenticed to the skipper of a coastal vessel. By 1752, he was in command of a sloop trading between New York and Canada. Sears established his reputation as a privateer during the French and Indian War, commanding a vessel from 1758 until 1761, when he lost his ship. He moved to New York City and had become successful enough to become a merchant investing in ships engaging in trade with the West Indies.
On October 31, 1765 the day before the Stamp Act was to take effect he was among the merchants assembled in New York City resolved to enforce opposition to distribution of the stamps and to curtail the importation of British goods. Sears organized and was a leader of the Sons of Liberty in 1765. They used violence and threats of violence to prevent the use of stamps. He was nicknamed "King Sears" for his influential role in organizing and leading the New York mob. He was at the head of nearly every demonstration of mob violence in New York City. He partnered with James DeLancey in opposition to the stamps and supported him in his 1768 election to the New York assembly. Sears and many of his followers were engaged in trade and they demanded that trade continue without stamps.
In 1766, Sears, John Lamb and three others formed a committee of correspondence to communicate with other Sons of Liberty groups in other provinces. After the Stamp Act was repealed the Sons of Liberty erected a Liberty pole to celebrate. When the British cut down the pole for the first time, Sears was injured in a confrontation with the British. In 1768, he and numerous New York merchants sent a petition to Parliament outlining their grievances on the state of trade. In 1769, when the New York assembly passed an appropriation for funding of the Quartering Act, he posted an inflammatory broadside entitled "To the betrayed inhabitants of the city and colony of New York".