Jonathan Sewall (August 24, 1729 – September 27, 1796) was the last Colonial attorney general of Massachusetts. He was born in Boston on August 24, 1729 to Jonathan Sewall Sr. and Mary (Payne) Sewall. Sewall's father was an unsuccessful merchant who died at a young age. However through scholarships, funds raised by his pastor William Cooper and with the help of his uncle, Chief Justice Stephen Sewall, Sewall was able to attend Harvard. Sewall graduated from Harvard College in 1748, and was a teacher in Salem until 1756. He married Esther Quincy, a daughter of merchant Edmund Quincy. After studying law, he began a successful practice in Charlestown and served as attorney general of Massachusetts from 1767 to 1775. In 1768 he was also appointed Judge of Admiralty for Nova Scotia.