State Route 611 (SR 611, OH 611) is an east–west state highway in the northern portion of the U.S. state of Ohio. The western terminus of State Route 611 is at a partial interchange with U.S. Route 6 in Lorain. Its eastern terminus is at a signalized intersection with State Route 254 in Avon.

The entirety of State Route 611 exists within northern Lorain County. No part of the highway is included as a component of the National Highway System.

State Route 611 made its debut in 1937. Originally, the highway began at U.S. Route 6 where it meets Colorado Avenue east of where U.S. Route 6 crosses the Black River near downtown Lorain, and followed Colorado Avenue southeast to where the current State Route 611 comes in at the intersection with Kansas Avenue and Henderson Drive. From there, the highway was routed along its current alignment to its eastern terminus at State Route 254 in Avon.

In 1946, State Route 611 took on the alignment that it follows today, as the result of a westward extension. From the intersection of Colorado Avenue, Kansas Avenue and Henderson Drive in Lorain, the highway was re-routed south onto Henderson Drive, which it used to cross the Black River, then turned southwesterly into a connection with 21st Street, which it followed heading west across Lorain to its current western terminus at U.S. Route 6 in the northwestern portion of the city.

The entire route is in Lorain County.