| John De Mott | |
| State: | New York |
| District: | 27th |
| Term Start: | March 4, 1845 |
| Term End: | March 3, 1847 |
| Predecessor: | Byram Green |
| Successor: | John M. Holley |
| Office2: | New York State Assembly |
| Term2: | 1833 |
| Birth Date: | 7 October 1790 |
| Birth Place: | Readington Township, New Jersey |
| Death Place: | Lodi, New York |
| Party: | Democratic |
| Branch: | New York militia |
| Rank: | Major general |
| Unit: | Thirty-eighth Brigade |
John De Mott (October 7, 1790 – July 31, 1870) was an American businessman and politician who served one term as a U.S. Representative from New York from 1845 to 1847.
Born in Readington, New Jersey, De Mott moved to Herkimer County, New York, in 1793 with his parents, who settled in what is now the town of Lodi, Seneca County.He attended the common schools.He pursued an academic course.Major general of the Thirty-eighth Brigade of the State militia.Supervisor in the town of Covert in 1823 and 1824 and of Lodi in 1826, 1827, 1829, and 1830.He engaged in mercantile pursuits in Lodi, New York, for more than forty years.He served as member of the State assembly in 1833.He was an unsuccessful candidate for election in 1840 to the Twenty-seventh Congress.
De Mott was elected as a Democrat to the Twenty-ninth Congress (March 4, 1845 – March 3, 1847).He was not a candidate for renomination in 1846.
He resumed his former business pursuits and also engaged in the banking business.
He died in Lodi, New York, July 31, 1870.He was interred in Evergreen Cemetery, Ovid, New York.