John Murdoch Harbert III (July 19, 1921 – March 31, 1995) was an American businessman. He is best known for building his international construction company, Harbert Corporation, into one of the world's largest, along with creating a personal wealth of well over $1.7 billion. Harbert lived with his wife Marguerite in the wealthy Birmingham, Alabama suburb of Mountain Brook.John is also the older brother of late Birmingham businessman Bill L. Harbert, who was a co-founder of Harbert Corp.