Sir John Roy Sambles FRS HonFInstP (born 1945) is an English experimental physicist and a former President of the Institute of Physics.

[1] Sambles, originally from Callington in Cornwall,[2] studied physics at Imperial College, London, gaining his BSc and PhD degrees there, and has since published over 550 papers in international journals.

He has a long and distinguished career researching the interaction of light with matter.

His group at Exeter studied a wide range of systems including: liquid crystal devices; iridescent butterfly wings; surface plasmons and microwave photonics.

[2] Sambles was knighted in the 2020 Birthday Honours for services to scientific research and outreach.