In the early 19th century, the Grand Junction Canal Company purchased 61½ acres of Park Wood from Kings College, Cambridge, 56 acres of land from the commissioners and 35 acres of the cottages and gardens of the hamlet of Park Hearne. The valley that the land covered was then dammed and flooded.

The reservoir was opened on 5 December 1811 as one of the feeder reservoirs for the Grand Junction Canal by engineer John Rennie and constructor Hugh Mackintosh. The link to the canal did not fulfil its intended purpose, since the water became polluted by the land and was eventually stopped as a feeder in 1851.

The reservoir was developed as a lido in 1933, with an Art Deco style main building designed by George W. Smith, together with an area reserved for swimming. The formal opening was by the Earl of Howe in 1936. The building included a cafe and changing rooms, and featured a terrace with steps leading into the enclosed swimming pool. The pool was built with a concrete base, and jetties on either side, but was open into the lido.

Rowing boats were available for hire, with boathouses on the western side of the reservoir. An enclosed boating area for children was later constructed. The reservoir became a popular location for water-skiing, and televised championships were often held there. Ruislip Yacht Club became based at the lido but in the 1970s, the reservoir water level was artificially lowered to prevent the flooding of nearby housing, making it unsuitable for yachting.

Ruislip Lido miniature railway was opened in 1945 with short trains being hauled by Prince Edward, an Atlantic-type steam locomotive. The line was less than a third of what it is today, as it was just a dog bone circuit on the south-east shore of the lido, running around the woods.

The Lido’s main Art Deco building was closed and became subject to vandalism. In June 1993 it was damaged beyond repair in an arson attack and was demolished in 1994. The building was replaced in 1996 by a restaurant named The Water’s Edge, built in a similar style.

In January 2010 Hillingdon Council unveiled an enhancement project for the lido, including reinstating the outdoor swimming area and establishing special boating areas.