It rises in central York County, at the junction of Carlisle Brook and Lords Brook in the town of Lyman. Lords Brook issues from Kennebunk Pond in Lyman. The Kennebunk River flows generally southeast, passing under Interstate 95 and U.S. Route 1. It flows past the town center of Kennebunkport, where it becomes navigable, and enters the Atlantic in Kennebunkport, approximately one-half mile (1 km) downstream from the town center.
^U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data. The National MapArchived 2012-03-29 at the Wayback Machine, accessed June 30, 2011
