A high school dropout, he had become a leading manufacturer of horse-drawn vehicles by 1890. When approached to become General Manager of Buick in 1904, he made a similar success and was soon president of this horseless vehicle company. In 1908 he arranged the incorporation by proxies of General Motors and quickly thereafter sold stock and with the proceeds acquired Oldsmobile. The acquisitions of Oakland (now Pontiac), Cadillac, and parts companies followed in short order.
In 1910, Durant became financially overextended and banking interests assumed control, forcing him from management of GM. He then partnered with Louis Chevrolet in the Chevrolet company, and regained control of GM in 1915 in another merger, but lost it for good in 1920 to the DuPont interests.
In 1921 he established a new Durant Motors company, initially with one brand but later, as he had with General Motors, acquiring a range of companies whose cars were aimed at different markets. The cheapest brand was the Star, aimed at the person who would otherwise buy the obsolescent Model T Ford, while the Durant cars were mid-market, the Princeton line (designed, prototyped, and marketed but never produced) competed with Packard and Cadillac, and the ultra-luxurious Locomobile was the top of the line. However, he was unable to duplicate his former success, and the financial woes of the time proved fatal as the company failed in 1933.
Driven from the automotive field, in his last years he operated bowling alleys.