State Highway 159 is a 33.6 mi (54.1 km) long state highway in far southern Colorado.

SH 159 starts in the south at the New Mexico state line where the road becomes New Mexico State Road 522 which heads south towards Taos, NM. From the state line the road heads north to meet U.S. Highway 160 at its north end just outside Fort Garland. There is only one town along the route, San Luis, which is at the road's midpoint. San Luis is also the site of SH 159's junction with State Highway 142, the only significant junction along the route.

The route was established in the 1920s and paved by 1938. The route remains as it was when established.

The entire route is located in Costilla County.