John P. Smol, OC OOnt FRS FRSC[2] is a Canadian ecologist, limnologist and paleolimnologist who is a Distinguished University Professor in the Department of Biology[3] at Queen's University, Kingston, Ontario, where he also held the Canada Research Chair in Environmental Change for the maximum of three 7-year terms (2001–2021).

[9] Smol works on a diverse range of subjects, most of which focus on using lake sediments to reconstruct past environmental trends.

Topics include: lake acidification caused by acid rain, sewage input and fertilizer runoff (eutrophication), studies of nutrient and contaminant transport by birds and other biovectors, and a large program on climatic change.

For about three decades, he has been leading research in the high Arctic, studying the present-day ecology of polar lakes and ponds, and then using paleolimnological approaches to determine how these ecosystems have been changing due to natural and anthropogenic stressors.

He held the Chair of the International Paleolimnology Association [14] for two three-year terms ending in August 2018, and until recently was President (2019–2022) of the Academy of Science, Royal Society of Canada.