Bull Lake is a lake in geographic Varley Township in Algoma District, Ontario, Canada. It is about long and wide, and lies at an elevation of . The primary inflows are unnamed creeks from Bridge Lake and West Twin Lake, and the primary outflow is Bull Creek, which flows into the Little White River, a tributary of the Mississagi River.
Bull Lake is about north north east of the community of Iron Bridge.
A second Bull Lake in Algoma District, Bull Lake (Boon Township), lies east southeast.