The Washington Downtown Historic District is a nationally recognized historic district located in Washington, Iowa, United States.

It was listed on the National Register of Historic Places in 2013.

The district contains a mix of civic and commercial buildings, fraternal clubs, churches, warehouses, automobile-related services, utility companies, theaters, and a newspaper office.

The civic buildings include the courthouse, county jail and sheriff's residence, post office, and the public library (both the old and new buildings).

The period of significance is from 1839, when the original town was platted, to 1966 when the jail/sheriff's residence was built.