| W. H. Plummer | |
| Office: | President pro tempore of the Washington Senate |
| Term Start: | January 11, 1897 |
| Term End: | January 9, 1899 |
| Predecessor: | B. C. Van Houten |
| Successor: | Augustus High |
| State Senate1: | Washington |
| District1: | 3rd |
| Term Start1: | January 11, 1897 |
| Term End1: | January 14, 1901 |
| Preceded1: | B. C. Van Houten |
| Succeeded1: | Warren W. Tolman |
| Birth Date: | 19 August 1860 |
| Birth Place: | Westboro, Massachusetts, U.S. |
| Death Place: | Los Angeles, California, U.S. |
| Party: | Democratic (1899–1926) |
| Otherparty: | Populist (before 1899) |
William H. Plummer (August 19, 1860 – December 22, 1926) was an American politician in the state of Washington. He served in the Washington State Senate from 1897 to 1901.[1] From 1897 to 1899, he was President pro tempore of the Senate.[2]
Born in Boston, Massachusetts,[3] he became "one of the best known attorneys of Eastern Washington".[3] He served as prosecuting attorney of Spokane County prior to his election to the state senate.[3] While serving in the senate, he "fathered the bill that banned gambling in the State of Washington".[3] He moved to Santa Ana, California around 1920, then returned to Spokane, Washington, and then moved to Los Angeles, California, around 1922, setting up a successful law practice there.[3]
Plummer died in his home in Arcadia, California, at the age of 66, following a month-long illness.[3] He was survived by his wife, Ella, and was interred at Pasadena, California.[3]