U.S. Route 177 (US-177) is a spur of U.S. Route 77. It currently runs for 233 miles (375 km) from South Haven, Kansas at US-81 to Madill, Oklahoma at US-70. It passes through the states of Kansas and Oklahoma.

U.S. Route 77 is a major north–south United States Numbered Highway which extends for 1,305 miles (2,100 km) in the central United States. As of 2005, Its southern terminus is in Brownsville, Texas, at Veteran's International Bridge on the Mexican border, where it connects with both Mexican Federal Highway 101 and Mexican Federal Highway 180, and the highway's northern terminus is in Sioux City, Iowa, at an interchange with Interstate 29 (I-29), less than 1⁄2 mile (800 m) north of the Nebraska state line.