Nanaimo Lakes are a chain of four lakes composed of three natural—First, Second, and Third Lakes—and one man-made, dammed lake, Fourth Lake, on the upper Nanaimo River, on Vancouver Island in British Columbia, Canada.

The lakes are in a highland transitional area between the southern Vancouver Island Ranges and the Nanaimo Lowland.

The 1:50,000 topographic map quadrangle 92F1 Nanaimo Lakes, published by Natural Resources Canada, is centred on the lakes. Note that lake names do not appear on all online mapping services, and Third Lake, not listed by the Watershed Roundtable, but listed in a 1919 guide, and on the Natural Resources Canada map, may not appear on some maps at all. A lake with a dam at the north end, named "Fourth Lake", is also shown on the map. First Lake and Second Lake, at c. 210 metres above sea level, are connected by a short stream. Fourth Lake Dam is privately owned and impounds 38,000,000 cubic metres (1.3×10 cu ft) of water, used for a paper mill.

• First Lake 49°05′45″N 124°10′00″W / 49.09583°N 124.16667°W / 49.09583; -124.16667 (First Lake), natural, about 2 miles (3.2 km) long
• Second Lake 49°05′45″N 124°13′00″W / 49.09583°N 124.21667°W / 49.09583; -124.21667 (Second Lake), natural, about 2 miles (3.2 km) long
• Third Lake 49°05′10″N 124°19′12″W / 49.08611°N 124.32000°W / 49.08611; -124.32000 (Third Lake), natural, much smaller than the others
• Fourth Lake 49°03′31″N 124°25′12″W / 49.05861°N 124.42000°W / 49.05861; -124.42000 (Fourth Lake), a reservoir, about 2.5 miles (4.0 km) long and 2 km in area

Timberwest owns four campsites on private land surrounding First Lake. The lake was stocked with up to 30,000 salmon or trout per year for recreational fishing beginning in 1905 through the early 21st century. Fourth Lake can be kayaked.

In March, 1945, a Fu-Go balloon bomb made in Yamaguchi Prefecture and launched from Japan landed at the lakes. Its firing circuits malfunctioned; it failed to detonate and was recovered and analyzed by a Canadian–American intelligence effort.

• List of lakes of British Columbia

• Butler, G.; Chapman, P.; Gullison, R.E.; Kellow, M.; Walker, S.; Wolf, J. (2014), Nanaimo River Baseline Report: social, environmental and economic values of the Nanaimo River and watershed (PDF) (2nd ed.) Unpublished report prepared for the Nanaimo & Area Land Trust. 312 pp.
• Coen, R. (2014). Fu-go: The Curious History of Japan's Balloon Bomb Attack on America. Studies in War, Society, and the Military Series. University of Nebraska Press. ISBN 978-0-8032-5667-5.
• Pochin, W.F. (1946). Angling and Hunting in British Columbia. Sun Directories.
• Williams, A.B. (1919). Rod & Creel in British Columbia. Progress Publishing Company. p. 143. Retrieved 10 July 2018.
• Yorath, C.J. (2005). The Geology of Southern Vancouver Island. Harbour Pub. ISBN 978-1-55017-362-8.

• Canada portal

• Davies, Gordon (1996). Living Rivers of British Columbia & Yukon. Living River of British Columbia & the Yukon. Ronsdale Press. ISBN 978-0-921870-37-1.