Marmon Group is an American industrial holding company headquartered in Chicago, Illinois.

Marmon Group primarily focuses on the industrial space, including companies that produce transportation equipment, electrical components, other industrial components, as well as service-based companies providing services in the construction and retail sectors.

Tank car manufacturing is a significant part of its business, including products which are sold through its subsidiaries Union Tank Car Company in the United States and Procor in Canada.

Berkshire Hathaway acquired controlling interest in Marmon in 2007 and became sole owner in 2013.

[3] Major acquisitions by Marmon Group have included Cerro Corporation (1976) and TransUnion (1981).