Interstate 135 (I-135) is an approximately 95.7-mile-long (154.0 km) auxiliary Interstate Highway in central and south-central Kansas, United States. I-135, which is signed as north–south, runs between I-35 and the Kansas Turnpike in Wichita north to I-70, U.S. Highway 40 (US-40), and US-81 in Salina. Except for the first 0.46 miles (0.74 km), I-135 overlaps US-81 its entire length. The route also runs through the cities of McPherson, Newton, and Park City. In 2021, work began to rebuild the northern junction with I-235.