| James Nathan Castle | |
| Birth Date: | 23 May 1836 |
| Birth Place: | Shefford, Lower Canada |
| Death Place: | Stillwater, Minnesota |
| State1: | Minnesota |
| District1: | 4th |
| Term Start1: | March 4, 1891 |
| Term End1: | March 3, 1893 |
| Preceded1: | Samuel Snider |
| Succeeded1: | Andrew Kiefer |
| Office2: | Member of the Minnesota Senate |
| Term2: | 1868 1878 1882 |
| Party: | Democratic |
| Occupation: | Lawyer |
James Nathan Castle (May 23, 1836 - January 2, 1903) was a U.S. Representative from Minnesota; born in Shefford in Lower Canada; he attended the public schools; studied law; moved to Afton, Washington County, Minnesota, in 1862 and taught school; completed his law studies; was admitted to the bar and practiced; moved to Stillwater, Washington County in 1865 and continued the practice of law; elected county attorney in 1866 to fill the unexpired term of his deceased brother; city attorney in 1868; elected to the Minnesota Senate in 1868, 1878, and 1882; elected as a Democrat to the 52nd United States Congress (March 4, 1891 - March 3, 1893); chairman of the United States House Committee on Mileage (52nd Congress); unsuccessful candidate for reelection in 1892 to the 53rd United States Congress; engaged in the practice of law until his death in Stillwater; interment in Fairview Cemetery.