Minnesota State Highway 123 (MN 123) is a 8.037-mile-long (12.934 km) highway in east-central Minnesota, which runs from its first intersection with State Highway 23 at Sandstone and continues east and then north to its northern terminus at its second intersection with State Highway 23 near Askov.

Highway 123 serves as an east–west and north–south route between Sandstone and Askov in east-central Minnesota.

Highway 123 passes briefly through Banning State Park.

The park entrance is located on nearby Highway 23, east of Interstate 35 near Askov.

The east-west portion of the highway was paved when it was marked.