Seth Hastings (April 8, 1762 – November 19, 1831) was a United States representative from Massachusetts. Born in Cambridge in the Province of Massachusetts Bay to Seth and Hannah (Soden) Hastings, he was a descendant of the colonist Thomas Hastings who came from the East Anglia region of England to the Massachusetts Bay Colony in 1634. He graduated from Harvard University in 1782, studied law, was admitted to the bar in 1786 and commenced practice in Mendon, Massachusetts. He was town treasurer in 1794 and 1795, and was elected one of the first school commissioners in 1796.