Klamath Agency is an unincorporated community in Klamath County, Oregon, United States, on Oregon Route 62 where Agency Creek enters Crooked Creek. Klamath Agency was an Indian agency for the Klamath Indian Reservation established May 12, 1866, on the shore of Agency Lake. The current site of the former agency is 3 miles (5 km) north of that location. The Klamath Reservation was terminated in 1961, but the community at Klamath Agency still exists. Klamath Agency post office was established in 1878 and ran until 1965, when the mail was instead routed to Chiloquin.