State Highway 66 (abbreviated SH-66) is a state highway in the U.S. state of Oklahoma, beginning at U.S. Highway 81 in El Reno and ending at U.S. Highway 60 near White Oak. The highway was designated in 1985 as a replacement for the decommissioned US-66. Although most of the highway follows Historic Route 66, the highway follows US-66's final alignment, joining Interstate 44 through Tulsa and Oklahoma City, while older versions of the route follow various city streets through both cities.