Dauphin Lake is located in western Manitoba near the city of Dauphin, Manitoba. The lake covers an area of 201 square miles (520 km2) and has a drainage basin of about 3,420 square miles (8,900 km2). The Mossy River drains the lake into Lake Winnipegosis. The basin is drained by seven major streams and has a total relief of 1,900 feet (580 m). The lake is located within the territory of three rural municipalities; in descending order of area they are the Rural Municipality of Ochre River, the Rural Municipality of Dauphin, and the Rural Municipality of Mossey River.
The lake provides wonderful recreational opportunities. Fishing is popular in both winter and summer, many people camp on the lake's shores and there are many cottages.
Dauphin Lake was named after the Dauphin of France, heir to the French throne, by Francois de La Verendrye in 1739.