U.S. Highway 87 is a north–south United States highway (though it is signed east–west in New Mexico) that runs for 1,998 miles (3,215 km) from northern Montana to southern Texas. Most of the portion from Billings, Montana, to Raton, New Mexico, is co-signed along Interstates 90 and 25. It is also co-signed along the majority of Interstate 27 in Texas.

As of 2004, the highway's northern terminus is Havre, Montana, at U.S. Highway 2. Its southern terminus is Port Lavaca, Texas.