| Ruthe Ridder | |
| State Senate: | Washington |
| District: | 35th |
| Term Start: | January 14, 1974 |
| Term End: | January 10, 1983 |
| Predecessor: | Robert Ridder |
| Successor: | Brad Owen |
| Birth Date: | 13 June 1929 |
| Birth Place: | Pullman, Washington, U.S. |
| Party: | Democratic |
| Spouse: | Robert Ridder |
Ruthe Ridder (born June 13, 1929) is an American former politician in the state of Washington. Ridder served in the Washington State Senate as a Democrat from the 35th District from 1974 to 1983. She attended the University of Washington and earned a Bachelor of Science degree in psychology. She served as the King County, Washington Assessor from 1984 to 1992.[1] [2]