John Lennox Monteith DSc, FRS[1] (3 September 1929 – 20 July 2012) was a British scientist who pioneered the application of physics to biology.

[2] Monteith's research on the role of the environment in agriculture,[8] the physics of crop microclimate, physiology of crop growth and yield, radiation climatology,[9] heat balance in animals,[10] and instrumentation for measuring physical and physiological variables in agriculture has been published in journals throughout the world.

His nomination for the Royal Society reads: Dr. Monteith has made outstanding contributions to knowledge and understanding of the micro-climatology of field crops.

His early work on the physics of dew is unlikely to be superseded: his radiation studies embrace a survey for the British Isles down to the attenuation and spectral changes as sunlight filters through a crop canopy.

He has been highly successful in devising or improving apparatus, and he has added much to the concept of "potential photosynthesis" as a measure of how a plant ought to grow in a given environment.