Silloth, or Silloth-on-Solway, is a port town and civil parish in the Cumberland district of Cumbria, England. The town stands on the coast of the Solway Firth, 18 miles (29 km) west of Carlisle. It was developed from the 1850s onwards around a new harbour, and also became a small seaside resort. At the 2021 census, the parish had a population of 2,749.