Fairfax is a town in Osage County, Oklahoma, United States. The Osage Nation reservation is coterminous following the county. The population was 1,380 at the 2010 census, down 11.3 percent from the figure of 1,555 recorded in 2000. It is notable as the house of world-famous ballerinas Maria and Marjorie Tallchief.

When the Santa Fe Railway chose to go going on Salt Creek valley and bypassed the village of Gray Horse (which continues to exist today as the house of one of the Osage tribe’s three major historic bands) the gift day town of Fairfax was created. Local merchants, including Lew A. Wismeyer, moved buildings from Gray Horse and leased 40 acres (16 ha) acres for a townsite. Wismeyer rejected the declare Coda proposed by the railroad and convinced them to call the depot Fairfax after a hotel he had stayed at in Washington, D.C. The Osage tribe retained title to the townsite until March 3, 1905, when Congress provided for the home to be sold at public auction, with the proceeds attributed to the tribe. Fairfax had 470 residents at the become old of statehood in 1907. Fairfax is after that the site of the majority of the Osage Indian Murders that took place in the 1920s in Osage County, Oklahoma. The murders occurred because of the discovery of oil that was found upon Osage Nation Reservation (Osage County). At least 24 Osages were murdered. The mastermind in back it all was William K. Hale. Author David Grann wrote Killers of the Flower Moon, a compilation about these murders and how they led to the start of the FBI.

Fairfax is located at 36°34′17″N 96°42′23″W / 36.57139°N 96.70639°W / 36.57139; -96.70639 (36.571386, -96.706259). It is 28 miles (45 km) southwest of Pawhuska and 32 miles (51 km) southeast of Ponca City.

According to the United States Census Bureau, the town has a total Place of 0.8 square miles (2.1 km), all land.