British-American colonial merchant and a judge in the Salem witchcraft trials, best remembered for his Diary (Massachusetts Historical Society; 3 vol., 1878–82), which provides a rewarding insight into the mind and life of the late New England Puritan.

A graduate of Harvard College (1671), Sewall began his public career in 1679, when he was made a “freeman”—a landowner with the right to participate in the government of the colony. He was manager of the colonial printing press (1681–84), member of the Council (1684–1725), and chief justice of the Superior Court (1718–28). He was also a commissioner of the Society for the Propagation of the Gospel in New England, an overseer of Harvard College, and captain of the Ancient and Honorable Artillery Company. In 1692 he was named by Gov. William Phips as one of the special commissioners appointed to try the Salem (Salem witch trials) witchcraft cases, in which 19 persons were condemned to death. Sewall was the only judge to admit the error of these decisions, standing silently in the Old South Church in Boston in 1697 while his confession of error and guilt was read aloud.

Sewall's writings include an early anti-slavery appeal, The Selling of Joseph (1700), A Memorial Relating to the Kennebeck Indians (1721), an argument for humane treatment of Indians, and unpublished verses and political and religious tracts.