K-26 is a short state highway located entirely within Cherokee County, Kansas. Its northern terminus is at K-66 in Galena and its southern terminus is at U.S. Route 166/U.S. Route 400 about two miles (3 km) from the Missouri/Kansas/Oklahoma corner. Its total length is 3.601 miles (5.795 km).

The route begins at an intersection with US 166 and US 400. K-26 continues southward with these concurrent routes; east of the intersection is Bagdad Road. The roadway heads north through a wooded area, passing several farms. Crossing Shoal Creek, the highway enters the community of South Galena and crosses 21st Road, which heads west toward Baxter Springs. K-26 enters the city of Galena as Main Street and heads to its terminus at K-66. Main Street continues toward a BNSF railway line.

The route is maintained by the Kansas Department of Transportation (KDOT), who is responsible for constructing and maintaining highways in the state. As part of this role, KDOT regularly surveys traffic on their highways. These surveys are most often presented in the form of annual average daily traffic, which is the number of vehicles that use a highway during an average day of the year. In 2010, KDOT calculated that a total of 2860 vehicles used the road daily, including 225 trucks. No part of the highway has been listed as part of the National Highway System, a network of roads important to the nation's defence, mobility, and economy.

K-26 was established by 1941 and originally began at US 69 in Crestline and ended at US 66 in Riverton. The road was previously designated as K-96 and was already paved at establishment. By 1951, K-26 was extended east along US 66 to Galena, then south on its current alignment to US 166. When US 66 was decommissioned, the segment between Crestline and Riverton became US 69 Alternate, and the section between Riverton and Galena was marked as K-66.

The entire route is in Cherokee County.