John Philip Grime (30 April 1935 – 19 April 2021) was an ecologist and emeritus professor at the University of Sheffield. He is best known for the universal adaptive strategy theory (UAST) and the twin filter model of community assembly with Simon Pierce, eco-evolutionary dynamics, the unimodal relationship between species richness and site productivity ("humped-back model"), the intermediate disturbance hypothesis, and DST classification (dominants, subordinates and transients).

Grime's 1979 book Plant Strategies and Vegetation Processes has been cited more than 1,200 times. Together with many influential scientific papers, it has made him a highly cited scientist. In an interview Grime has stated that "Ecology lacks a Periodic Table", quoting Richard Southwood.