The Sankey Viaduct is a railway viaduct in Newton-le-Willows in North West England. The majority of the viaduct is located within the borough of St Helens, Merseyside, with approximately a third to west of Sankey Brook being located within the borough of Warrington, Cheshire. It is a designated Grade I listed building and has been described as being "the earliest major railway viaduct in the world".