Iowa Highway 146 is a state highway in central Iowa. It runs in a north–south orientation and is 43 miles (69 km) long. Iowa 146 begins at an intersection with U.S. Route 63 at New Sharon, and ends at a freeway interchange with U.S. Highway 30 at Le Grand. While the route Iowa 146 takes has remained the same since its creation, the highway has been extended at least twice because of realignments of U.S. Route 30 near Le Grand. The northernmost 2 miles (3.2 km) were once part of the Lincoln Highway.

Marshall County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 40,105. The county seat and largest city is Marshalltown. The county was formed on January 13, 1846, and named after John Marshall, Chief Justice of the United States Supreme Court.