Martin Mechanical Contractors was founded in Athens, Georgia in 1952 as Maynard Sheet Metal Works by Ruben Maynard. When, in 1957, Paul Martin purchased half of the company, it became Maynard & Martin, Inc. In 1962, Mr. Martin purchased Mr. Maynard's stock and renamed the company Martin Mechanical Contractors, Inc.

In 1997, Paul Minish, Vice President of Field Operations, and long time Martin Mechanical employee R. Jack Dunagan purchased the company and continued to operate under the Martin Mechanical name. Because both men were integral parts of the business, the transition in ownership was seamless.

R. Jack Dunagan passed away in 2005 and his son, Jack Dunagan II, who was serving as Mechanical Department head, assumed the roles of Vice President of Operations and head of the Plumbing Department. In 2008, Jack Dunagan II acquired Paul Minish's stake in the company. Mr. Dunagan is now president, overseeing day to day company operations as well as developing long term strategies for the growth and sustainability of Martin Mechanical.