A native of Scotland, Indiana, John C. McElroy received his BSEE in the communications option from Purdue University in 1941. After five years with the U.S. Navy, he joined Collins Radio Company as a development engineer. He became the assistant director of engineering for the Cedar Rapids region of Collins in 1953 and was named vice president of engineering of the region in 1962. Under his supervision space-borne telecommunications systems were perfected for the Mercury, Gemini and Apollo programs. In 1966, McElroy became vice president of marketing for the Dallas region and worked with microwave, scatter, broadcast, marine, and data communications systems. In 1971, he added the responsibilities of general manager of the region to his work. In 1973 he became vice president and general manager of the London International operations with overall responsibilities for subsidiary companies in Europe, Africa, and the Middle East. He retired in 1974 after having devoted 28 years of service to Collins.

McElroy soon launched a second career as an independent consultant on both the national and international levels. He consulted in such diverse areas as underground coal mining processes, land vehicle position monitoring, and positioning products for a non-US telephone central office switching designer-producer.

McElroy, is a Senior Member of IEEE, retiring from consulting in 1989.