State Route 598 (SR 598) is a 23.43-mile-long (37.71 km) north–south state highway in the northern portion of the U.S. state of Ohio. The southern terminus of SR 598 is at a signalized intersection where it meets SR 19, SR 61 and SR 309 in Galion. Its northern terminus is at SR 103 nearly 1.75 miles (2.82 km) east of Willard.