Each county has a circuit court, which is a state trial court of general jurisdiction. However, except for cases involving the termination of parental rights, Gilliam, Sherman and Wheeler Counties also have “county courts,” which exercise jurisdiction in juvenile cases. In addition, Gilliam, Grant, Harney, Malheur, Sherman and Wheeler Counties’ county courts exercise jurisdiction in probate, adoption, guardianship and conservatorship cases.

Circuit court judges are elected on a nonpartisan ballot for six year terms. They must be citizens of the United States, members of the Oregon State Bar, residents of Oregon for at least three years and residents of their judicial district for a least one year, except Multnomah County judges who may reside within ten miles of the county. There are 179 circuit judges serving 36 counties. The circuit judges are grouped in 27 geographical areas called judicial districts. Of the 179, Multnomah County District has 38 circuit judges; Lane, Marion and Washington, 15; Clackamas, 11; Jackson, 10; Deschutes, 9; Coos/Curry, 6; Douglas, Josephine, Klamath, Linn and Umatilla/Morrow districts have 5; Yamhill and Hood River/Wasco/Sherman/Wheeler/Gilliam districts have 4; Benton, Clatsop, Columbia, Lincoln, Polk and Crook/Jefferson districts have 3; Malheur, Tillamook, Union/Wallowa districts have 2 and Baker, Lake, Grant/Harney districts have 1.

To expedite judicial business, the chief justice of the Supreme Court may assign any circuit judge to sit in any judicial district in the state.​