Coate Water is a country park situated 5km to the southeast of central Swindon, England, near junction 15 of the M4. It takes its name from its main feature, a reservoir originally built to provide water for the Wilts & Berks Canal.
The reservoir formed a 70acre lake, built in 1822 by diverting the River Cole. Its primary purpose was to provide water for the canal and it remained outside the borough of Swindon until the borough's expansion in 1928.
In 1914, with the canal abandoned, Coate became a pleasure park; changing rooms and a wooden diving board were added. In 1935 the wooden diving platform was replaced with a 33ft high concrete platform in an Art Deco style which has been praised by English Heritage and, although swimming in the lake has been prohibited since 1958, it was given Grade II listed protection in 2013. Now named Coate Water Country Park, the lake is both a leisure facility and a nature reserve.