K-181 is a 70.2-mile-long (113.0 km) north–south state highway which runs through several counties in the north central part of the U.S. state of Kansas. K-181's southern terminus is at K-232 southeast of Lucas by Wilson Lake Dam, and the northern terminus is at U.S. Highway 36 (US-36) and US-281 south of Lebanon. Along the way the highway intersects US-24 and K-9 in Downs.