| Official Name: | Washington Township |
| Settlement Type: | Township |
| Subdivision Type: | Country |
| Subdivision Type1: | State |
| Subdivision Type2: | County |
| Subdivision Name2: | Story |
| Unit Pref: | Imperial |
| Area Total Sq Mi: | 35.1 |
| Area Land Sq Mi: | 35.1 |
| Area Water Sq Mi: | 0.0 |
| Area Water Percent: | 0.0 |
| Population As Of: | 2000 |
| Population Total: | 35,477 |
| Population Density Sq Mi: | 1012 |
| Elevation Ft: | 971 |
| Coordinates: | 41.9911°N -93.6414°W |
| Postal Code Type: | ZIP Code |
| Postal Code: | 50010 |
| Area Code: | 515 |
Washington Township is a township in Story County, Iowa, United States. As of the 2000 census, its population was 35,477.
Washington Township covers an area of 35.1sqmi and contains the incorporated town of Ames, as well as part of Kelley. According to the USGS, it contains five cemeteries: Ontario Cemetery, Ames Municipal Cemetery, Memorial Gardens Cemetery, College Cemetery and Sunday Cemetery.
U.S. Route 69 runs north–south through the township and U.S. Route 30 runs east–west.
Washington Township is adjacent to Franklin, Grant and Palestine townships.