James Duff

Duff studied business at Utah Valley University.⁠[1]

Southern Tire Mart was founded in 1973 in Columbia, Mississippi, by Duff’s father, Ernest Duff, a prominent lawyer in the town who intended the business as a side investment. As it grew and needed dedicated management, his two sons, Tommy and Jim, joined the family business after finishing their college careers.⁠[2]

Ernest Duff sold the tire dealership in 1998; in 2003 James Duff and his brother Thomas Duff bought it back.⁠[3][4]

In 2007 the brothers started the holding company Duff Capital Investors.⁠[3]

In 2012 the Duff brothers made a significant contribution to the University of Southern Mississippi’s athletic department, and the university named its athletic center the Jim and Thomas Duff Athletic Center in their honor. In 2013 they provided a truck and trailer to carry the football team’s equipment to games and cover its operating costs each season; in 2016 they made another contribution for locker room renovations and new offices at the center.⁠[5]

On July 15, 2013, Frozen Food Express Industries announced a merger agreement under which Duff Brothers Capital Corporation would acquire it for $2.10 per share in cash, valuing Frozen Food Express at about $38.2 million in equity value. Duff Brothers Capital Corporation was wholly owned by Thomas and James Duff and was an affiliate of KLLM Transport Services LLC, both indirectly owned by the brothers.⁠[6]

The merger was completed on August 19, 2013, and Frozen Food Express became a wholly owned subsidiary of the acquirer.⁠[7]

On April 27, 2016, the University of Southern Mississippi’s College of Business honored the Duff brothers as its 2016 Entrepreneurs of the Year at a ceremony at the Trent Lott Center. Duff Capital Investors, headquartered in Columbia, Mississippi, then comprised 11 businesses with more than 10,000 employees and annual revenue of more than $2 billion; its companies included Southern Tire Mart, KLLM Transport Services, Frozen Food Express, Forest Products Transports, T.L. Wallace Construction, DeepWell Energy Services, Southern Insurance Group, Pine Belt Ford, Pine Belt Chevrolet, Magnolia Grille and Magnolia Inn.⁠[5]

In December 2016 James Duff received an honorary doctorate from the University of Southern Mississippi.⁠[8]

In 2017 the Duff brothers gave $1 million to create the Ernest R. Duff Flagship Constellation Fund, honoring their father, a 1955 graduate of the University of Mississippi law school. In 2020 they gave $26 million to build the Jim and Thomas Duff Center for Science and Technology Innovation; the 202,000-square-foot building opened in August 2024 as the largest academic project in the university’s history.⁠[1]

In 2020 the Duff brothers pledged $30 million in planned gifts to the University of Southern Mississippi, the largest bequests in its history; each had already given $1 million or more, cumulatively, to its academics and athletics.⁠[8]

On January 4, 2021, Southern Tire Mart and Pilot Company announced a strategic alliance: from January 1, 2021, the new venture assumed management of the 35 existing Pilot Flying J Truck Care maintenance facilities and planned to build more than 100 more locations over the next 18 months, while customers gained access to Southern Tire Mart’s 160 locations nationwide.⁠[9]

In September 2021 the trade magazine Modern Tire Dealer named Jim and Tommy Duff its 2021 Tire Dealers of the Year, an award established in 1993. Southern Tire Mart, headquartered in Columbia, Mississippi, then operated 19 Bandag manufacturing facilities and 140 commercial, retail and service locations and employed more than 3,600 people in 14 states; it sold more than 3 million truck tires and 2 million retread tires in 2020.⁠[8]

In November 2024 the University of Mississippi’s Women’s Council gave the Duff brothers its 2024 Legacy Award. Duff Capital Investors then had 22 business units and $5.5 billion in revenue and was the largest privately owned business in Mississippi.⁠[1]

James Duff said: “we want to try to help the students in our state help themselves and their communities.”⁠[1]

In 2026 Duff Capital Investors had more than 20 businesses with total revenue of about $6 billion; Southern Tire Mart sold more than 4 million new tires and 2.5 million truck tire retreads a year and was opening locations at Pilot Flying J truck stops.⁠[4]

As of September 27, 2026, ForbesForbesForbes is an American business media brand that began with Forbes magazine, founded by B.C. Forbes in 1917. It is known for rankings such as the Forbes 400, the World’s Billionaires list and 30 Under 30, and operates Forbes.com, ForbesLive events and licensed editions in 81 countries. Since 2014 a majority stake has been held by the Hong Kong investment group Integrated Whale Media; a 2021 plan to list on the New York Stock Exchange through a special purpose acquisition company was terminated in 2022. It is headquartered in Jersey City, New Jersey.Open the full entry’ real-time billionaires list estimated James Duff’s net worth at $4.5 billion; he and his brother Thomas Duff were the only billionaires in Mississippi.⁠[4]

The Duff brothers have also supported Mississippi State University’s Jim and Thomas Duff Center for Autism and Developmental Disabilities and its Department of Kinesiology.⁠[1]

Southern Tire Mart: Official website: https://stmtires.com/ (opens in a new window).⁠[2]