The Whitby, Redcar and Middlesbrough Union Railway (WRMU), a.k.a. the Whitby–Loftus Line, was a railway line in North Yorkshire, England, built between 1871 and 1886, running from Loftus on the Yorkshire coast to the Esk at Whitby, and connecting Middlesbrough to Whitby along the coast.

Whitby is a seaside town, port and civil parish in North Yorkshire, England. It is on the Yorkshire Coast at the mouth of the River Esk. It has a maritime, mineral and tourist economy. The fishing port emerged during the Middle Ages, supporting important herring and whaling fleets, and was where Captain Cook learned seamanship and, coincidentally, where his first vessel to explore the southern ocean, HMS Endeavour, was built. Jet and alum were mined locally, and Whitby jet, which was mined by the Romans and Victorians, became fashionable during the 19th century.