John Clarence Karcher (June 4, 1894 – July 13, 1978) was an American geophysicist and businessman. He invented and eventually commercialized the reflection seismograph, applying for patents on this in 1919. In doing this he created the means by which most of the world's oil reserves have been discovered. In 1930 he and Eugene McDermott founded Geophysical Service Incorporated, a pioneering provider of seismic exploration services to the petroleum industry. This company later spun off what would become Texas Instruments.