U.S. Route 73 (US 73) is a north–south United States highway that runs for 113 miles (182 km) from northeast Kansas to southeast Nebraska.

The highway's southern terminus is Bonner Springs, Kansas at I-70.

It goes northwesterly from Leavenworth, meeting K-192 near Easton and at Atchison, turns west.

After a brief northwesterly routing through Reserve, US 73 and US 159 turn north and enter Nebraska.

A few miles north of Falls City, U.S. Route 73 turns west, passes through Verdon, and ends at U.S. Route 75 just north of Dawson, Nebraska.The original southern terminus was at Atoka, Oklahoma at an intersection with U.S. Highway 75.

[4] In 1932, the highway was extended to South Sioux City, Nebraska.

In 1984, U.S. 75 was removed from western Iowa along Interstate 29 and placed on U.S. 73's route, superseding it through Omaha, Nebraska and truncating the highway to its present northern terminus near Dawson, Nebraska.