Although the headwaters of the Chagrin River are near Aurora and Mantua, the main river starts coming together close to Chagrin Falls near the Cuyahoga County/Geauga County line about 15 miles southeast of Cleveland in northeastern Ohio.
The river forks with the main branch heading north and a smaller branch heading to the northeast to flow through Chardon before returning to a northerly tack. The two branchs merge in Willoughby before emptying into Lake Erie at Mentor.
