Upper Rideau Lake is a freshwater lake located in the municipality of Rideau Lakes, United Counties of Leeds and Grenville in Eastern Ontario, Canada. It is located in the Saint Lawrence River drainage basin and is the lake with the highest altitude within the Rideau Canal system.

The Rideau Canal is a 202 kilometre long canal that links the Ottawa River at Ottawa with the Cataraqui River and Lake Ontario at Kingston, Ontario, Canada. Its 46 locks raise boats from the Ottawa River 83 metres upstream along the Rideau River to the Rideau Lakes, and from there drop 50 metres downstream along the Cataraqui River to Kingston.