The River Clyde (Scottish Gaelic: Abhainn Chluaidh, pronounced [ˈavɪɲ ˈxl̪ˠuəj]) is a major river of western Scotland and the third-longest in the country at about 170 kilometres (110 mi) in length. Its river network extends to 4,244 km and drains a basin of 1,903 km, expanding to 3,854 km when the Clyde estuary system with the Kelvin, White Cart, Black Cart and Leven is included. Around 1.79 million people, 33.8% of Scotland's population, live within this catchment. The river rises in the Lowther Hills and flows north-west through South Lanarkshire and Glasgow before entering the Firth of Clyde.
From the late 18th century the upper estuary and river through Glasgow were systematically engineered using groynes, longitudinal training walls and continuous dredging, and by removing rocky obstructions such as a large part of the Elderslie Rock. This was done to enable ocean-going access and support Glasgow's rise as a world centre of shipbuilding and marine engineering in the 19th and 20th centuries.