John MacPherson Berrien (August 23, 1781–January 1, 1856) of Georgia was a United States Senator and Andrew Jackson's Attorney General.

Born at Rocky Hill, near Princeton, New Jersey, he moved with his parents to Savannah, Georgia, in 1782; was graduated from Princeton College in 1796; studied law in Savannah; was admitted to the bar at the age of 18, and began practice in Louisville, Georgia in 1799. After he returned to Savannah he was elected solicitor of the eastern judicial circuit of Georgia in 1809; judge of the same circuit from 1810 until January 30, 1821, when he resigned. He served as captain of the Georgia Hussars , a Savannah volunteer company, in the War of 1812.

A member of the Georgia Senate from 1822 to 1823; he was elected as a Jacksonian Democrat to the United States Senate and served from March 4, 1825, until March 9, 1829 when resigned to accept the position of Attorney General in the Cabinet of President Andrew Jackson and served from March 9, 1829, until June 22, 1831, when he resigned. After leaving the Cabinet he resumed the practice of law until he was again elected, as a Whig, to the U.S. Senate and served from March 4, 1841, until May 1845, when he again resigned to accept an appointment to the supreme court of Georgia; again elected in 1845 to the United States Senate to fill the vacancy caused by his second resignation; reelected in 1846 and served from November 13, 1845, until May 28, 1852, when he resigned for the third time.

He served as the chairman of the U.S. Senate Committee on the Judiciary in the 20th, 26th and 27th Congresses. He was president of the American Party convention at Milledgeville in 1855; and died in Savannah on January 1, 1856. He is interred in Laurel Grove Cemetery. Berrien County, Georgia and Berrien County, Michigan (settled when he was attorney general), are named in his honor.