State Route 240 (SR 240) is a state highway in the U.S. state of Washington. It travels diagonally from northwest to southwest within Benton County, serving the Hanford Nuclear Reservation and the Tri-Cities region. The highway begins at a junction with SR 24 and travels around Richland on a limited-access bypass. From there, it briefly overlaps Interstate 182 (I-182) and continues southeast as a freeway along the Columbia River into Kennewick, terminating at an interchange with U.S. Route 395 (US 395). SR 240 is one of the busiest highways in the Tri-Cities region, with a daily average of 76,000 vehicles on a section crossing the Yakima River Delta.