Runcorn, town, Halton unitary authority, historic county of Cheshire, northwestern England.
It lies on the southern shore of the River Mersey 15 miles (24 km) upstream from the port of Liverpool. The main industry is the production of chemicals. Railway and road bridges connect the town with Widnes on the north shore of the Mersey. Pop. (2001) 60,072; (2011) 61,789.