Ashdale Junction is an unincorporated community in Carroll County, Illinois, United States. Ashdale Junction is located along the Milwaukee Road railroad line east of Mount Carroll. Ashdale Junction marks the former site of the junction between the main line of the Milwaukee Road and the "Ashdale cutoff," which allowed some trains to bypass the yard and steep grade at Savanna, rejoining the main line at Ebner. The 15-mile cutoff, running along , was built by the "Ashdale and Thomson Railroad" (a subsidiary of the Milwaukee Road) in 1902, and began carrying trains such as the Southwest Limited in 1903. It was part of a larger bypass project running across Iowa, called the "Kansas City Cutoff." The Ashdale cutoff was abandoned in 1952.