The Clatsop County Circuit Court is the 18th Judicial District of Oregon. Clatsop County's judicial district has three elected judges:
- Judge Beau Peterson, Presiding Judge
- Judge Dawn McIntosh, Circuit Court Judge
- Judge Kirk Wintermute, Circuit Court Judge
The court is housed in an historic courthouse which was built in 1908 and was later added to the National Register of Historic Places. Astoria was the first permanent United States settlement on the Pacific coast and is historically significant for operating the first U.S. post office west of the Rocky Mountains.