Rusty Lake is a lake in Meadow Lake Provincial Park in the Canadian Province of Saskatchewan in the boreal forest ecozone of Canada. The lake is the first of six notable lakes in the Rusty Creek watershed part of Meadow Lake Provincial Park. The other lakes include First Mustus, Second Mustus, Third Mustus, Peitahigan, and Fourth Mustus.

Rusty Lake, Rusty Creek, and the other lakes are part of the Waterhen River drainage basin. The Waterhen River is a tributary of the Beaver River, which flows north into Lac Île-à-la-Crosse and the Churchill River, a major tributary in the Hudson Bay drainage basin. Highway 224 runs along the northern shore of Rusty Lake.

Fish species found in the lake include northern pike, walleye, and yellow perch.

• List of lakes of Saskatchewan
• Tourism in Saskatchewan