How many counties are there in Oregon? As of 2024, there are a total of 36 counties in the state of Oregon. Among them, Clackamas County is the oldest one (established in 1843) while Deschutes County is the youngest (established in 1916). With population of 790,670, Multnomah County is the most populated. The biggest county by land area is Harney County (26,250 km²) and the smallest is Multnomah County (1,127 km²).
