K-33 begins at an intersection with K-68 east of Ottawa in Franklin County and heads north on a two-lane road through rolling plains. Approximately four miles (6.4 km) north of this intersection, the route curves to the east momentarily before curving back to the north. Here, the highway intersects Interstate 35 (I-35) and US-50 at a diamond interchange. North of this interchange, K-33 enters the city of Wellsville. In Wellsville, the highway crosses the BNSF Railway. Continuing north, K-33 leaves Wellsville and Franklin County, and enters Douglas County. About two miles (3.2 km) north of the county line, the highway ends at an intersection with US-56.