James Madison Morton Jr. (August 24, 1869 – June 26, 1940) was a longtime United States federal judge.
Morton was born and lived throughout his life in Fall River, Massachusetts. Morton was born in Fall River, Massachusetts. He received an A.B. from Harvard College in 1891, followed by an A.M. from that institution in 1894, and an LL.B. from Harvard Law School in 1894. He was a lawyer in private practice in Fall River, Massachusetts from 1894 to 1912.
Morton was nominated by President William H. Taft on August 9, 1912, to a seat on the United States District Court for the District of Massachusetts vacated by Frederic Dodge. Morton was confirmed by the United States Senate on August 12, 1912, and received his commission the same day.
On December 15, 1931, President Herbert Hoover nominated Morton for elevation to a seat on the United States Court of Appeals for the First Circuit vacated by George Weston Anderson. Morton's elevation was confirmed by the Senate on January 6, 1932, and he received his commission on January 9, 1932. He assumed what is now referred to as senior status in 1939, serving in that capacity until his death the following year. He died in Fall River, Massachusetts.