Lake of Bays was previously known as Baptiste Lake, Forked Lake and Lake of Two Bays. It was named Lake of Bays in 1853 by Alexander Murray of the Geological Survey of Canada. The Lake of Bays township is in named for the lake.
The lake is fed by Oxtongue River, as well as other rivers and creeks. The irregular shape of the lake is defined by many bays such as Rabbit’s Bay, Burnt Island Bay, Whitehouse Bay, Portage Bay, Haystack Bay, Ten Mile Bay, Dwight Bay,Trading Bay and Murky Bay.