Burt Lake is a 17,120 acre (69 kmē) lake in Cheboygan County, Michigan. The western shore of the lake is on the boundary with Emmet County. The lake is named after William Austin Burt, who, together with John Mullett, made a federal survey of the area from 1840 to 1843.
The lake is approximately 10 miles (16 km) long from north to south, about 5 miles (8 km) at its widest, and 73 feet (22 m) at its deepest. Major inflows to the lake are the Maple River, which connects with nearby Douglas Lake, the Crooked River, which connects with nearby Crooked Lake, and the Sturgeon River which enters the lake near the point where the Indian River flows out of the lake into nearby Mullett Lake.
The lake is part of the great Inland Waterway, by which one can boat from Crooked Lake several miles (km) east of Petoskey on the Little Traverse Bay of Lake Michigan across the northern tip of the lower peninsula's so-called mitten to Cheboygan on Lake Huron. Along with nearby Mullett Lake and Black Lake, it is noted for its population of Lake Sturgeon, which briefly held the record of largest sturgeon caught in the USA.
YMCA Camp Al-Gon-Quian  and Burt Lake State Park are both located on the southern shore of the lake. The unincorporated community of Burt Lake is on the southwest shore on M-68. Interstate 75 passes to the east of the lake, with two interchanges near the south end of the lake at the unincorporated community of Indian River.