U.S. Route 24 or U.S. Highway 24 (US 24) is one of the original United States Numbered Highways of 1926. It originally ran from Pontiac, Michigan, in the east to Kansas City, Missouri, in the west. Today, the highway's eastern terminus is in Independence Township, Michigan, at an intersection with Interstate 75 (I-75), and its western terminus is near Minturn, Colorado, at an intersection with I-70. The highway transitions from north–south to east–west signage at the Ohio–Michigan state line.

Colby is a city in and the county seat of Thomas County, Kansas, United States. As of the 2020 census, the population of the city was 5,570.