| Platt A. Preston | |
| Office: | Member of the Washington State Senate |
| Constituency: | 10th |
| Term Start: | January 7, 1891 |
| Term End: | January 9, 1893 |
| Predecessor: | Eugene T. Wilson |
| Successor: | David Miller |
| Constituency1: | 8th |
| Term Start1: | November 6, 1889 |
| Term End1: | January 7, 1891 |
| Predecessor1: | Constituency established |
| Successor1: | C. G. Austin |
| Birth Name: | Platt Adams Preston |
| Birth Date: | 1 November 1837 |
| Birth Place: | Saratoga, New York, U.S. |
| Death Place: | Galveston, Texas, U.S. |
| Party: | Republican |
Platt Adams Preston (November 1, 1837 – March 12, 1900) was an American politician in the state of Washington. He served in the Washington State Senate from 1889 to 1893 (1889 - 91 for district 8, 1891 - 93 for district 10).[1]