| James Madison Morton Jr. | |
| Office: | Senior Judge of the United States Court of Appeals for the First Circuit |
| Term Start: | September 30, 1939 |
| Term End: | June 26, 1940 |
| Office1: | Judge of the United States Court of Appeals for the First Circuit |
| Term Start1: | January 9, 1932 |
| Term End1: | September 30, 1939 |
| Appointer1: | Herbert Hoover |
| Predecessor1: | George W. Anderson |
| Successor1: | John Christopher Mahoney |
| Office2: | Judge of the United States District Court for the District of Massachusetts |
| Term Start2: | August 12, 1912 |
| Term End2: | January 19, 1932 |
| Appointer2: | William Howard Taft |
| Predecessor2: | Frederic Dodge |
| Successor2: | Hugh Dean McLellan |
| Birth Name: | James Madison Morton Jr. |
| Birth Date: | 24 August 1869 |
| Birth Place: | Fall River, Massachusetts |
| Death Place: | Fall River, Massachusetts |
| Education: | Harvard University (AB, AM) Harvard Law School (LLB) |
| Signature: | JamesMadisonMortonJr (signature).jpg |
James Madison Morton Jr. (August 24, 1869 – June 26, 1940) was a United States circuit judge of the United States Court of Appeals for the First Circuit and previously was a United States District Judge of the United States District Court for the District of Massachusetts.
Born on August 24, 1869, in Fall River, Massachusetts, Morton's father, James Madison Morton Sr., was a prominent Boston lawyer who eventually served on the state supreme court. Morton received an Artium Baccalaureus degree in 1891 from Harvard University and received an Artium Magister degree in 1894 from the same institution. He received a Bachelor of Laws in 1894 from Harvard Law School. He was in private practice in Fall River from 1894 to 1912.
Morton was nominated by President William Howard Taft on August 9, 1912, to a seat on the United States District Court for the District of Massachusetts vacated by Judge Frederic Dodge. He was confirmed by the United States Senate on August 12, 1912, and received his commission the same day. His service terminated on January 19, 1932, due to his elevation to the First Circuit.
Morton was nominated by President Herbert Hoover on December 15, 1931, to a seat on the United States Court of Appeals for the First Circuit vacated by Judge George W. Anderson. He was confirmed by the Senate on January 6, 1932, and received his commission on January 9, 1932. He assumed senior status on September 30, 1939. His service terminated on June 26, 1940, due to his death in Fall River.