| James Marion Baker | |
| Ambassador From1: | United States |
| Country1: | Thailand |
| Appointer1: | Franklin D. Roosevelt |
| Term Start1: | December 9, 1933 |
| Term End1: | May 2, 1936 |
| Predecessor1: | David E. Kaufman |
| Successor1: | Edwin L. Neville |
| Office2: | 12th Secretary of the United States Senate |
| Term Start2: | March 13, 1913 |
| Term End2: | May 19, 1919 |
| Predecessor2: | Charles G. Bennett |
| Successor2: | George A. Sanderson |
| Birth Date: | 18 August 1861 |
| Birth Place: | South Carolina, United States |
| Party: | Democratic |
James Marion Baker (August 18, 1861 – November 21, 1940)[1] was an American political figure, who held the position of Secretary of the United States Senate from 1913 to 1919.
Baker was born in South Carolina, and came to serve as the assistant librarian of the United States Senate. In 1913, Baker was elected by the new, Democratic senate, as the eleventh secretary of the Senate after serving twenty years as assistant librarian.
At the retaking of the Senate by the Republican Party in 1919, Baker was replaced by George A. Sanderson, and President Woodrow Wilson appointed Baker deputy commissioner of internal revenue.
Baker left the government when Woodrow Wilson left the White House, and established a law firm.
In 1931, Baker retired to assist with Franklin D. Roosevelt's presidential campaign. Baker later became a minister to Thailand in the Roosevelt administration, until retiring due to poor health in 1937.