Iowa Highway 4 is a state highway which runs from north to south across the state of Iowa. It is 146 miles (235 km) long, beginning at an intersection with Iowa Highway 44 in Panora and ending at the Minnesota state line north of Estherville. It continues north as Minnesota State Highway 4. The route was created on January 1, 1969, when several route designations were changed to match other states' route numbers. Before 1969, Iowa 4 was known as Iowa 17.

Iowa Highway 44 (Iowa 44) is an east–west highway in the central and west-central portions of the state. It runs parallel to Interstate 80, which runs 10 miles (16 km) to the south for most of Iowa 44's route. Iowa 44 begins at its junction with U.S. Highway 30 four miles (6 km) northeast of Logan. It ends at an interchange with the Iowa Highway 141 freeway at Grimes. Iowa 44 was created in 1969 when Iowa Highway 64 was shortened to its current route in eastern Iowa. Most of the route is a part of the Western Skies Scenic Byway.