Edmund Quincy III (/ˈkwɪnzi/; 1681–1737) was an American merchant and judge.

Four lived to adulthood, including Edmund Quincy IV and Dorothy Quincy, who was the topic of a famous poem by Oliver Wendell Holmes Sr.[1][2] Like his father and grandfather, he was deeply involved with the affairs of the Massachusetts colony.

He was a magistrate, Supreme Court judge from 1718 until his death, and a colonel in the Massachusetts militia.

In 1737, he was appointed to a commission to settle the boundary between Massachusetts and New Hampshire.

The colony built a monument at his grave in Brunhill Fields Burial Ground in London and gave 1,000 acres (4.0 km2) in Lenox to his family as a tribute for all of his efforts.