(浜松ホトニクス株式会社, Hamamatsu Hotonikusu Kabushiki-Kaisha) is a Japanese manufacturer of optical sensors (including photomultiplier tubes), electric light sources, and other optical devices and their applied instruments for scientific, technical and medical use.

[2][3] The company was founded in 1953 by Heihachiro Horiuchi, a former student of Kenjiro Takayanagi, who is known as "the father of Japanese television".

[4] Hermann Simon, a leading German business author and thinker, mentioned Hamamatsu in his book titled Hidden Champions of the Twenty-First Century: The Success Strategies of Unknown World Market Leaders as an example of a "Hidden Champion".

[2] As examples of uses, Hamamatsu CCD image sensors are used at the Subaru Telescope of the National Astronomical Observatory of Japan,[5] and the sensors made by the company also helped confirm the existence of the Higgs boson in research that led to the 2013 Nobel Physics prize.

[6] Hamamatsu Photonics' photomultiplier tubes (PMTs) were used in the Super-Kamiokande neutrino detector facility at the University of Tokyo where 2015 Nobel Prize Laureate Takaaki Kajita conducted his research.