John Warne Gates (May 18, 1855 – August 9, 1911), also known as "Bet-a-Million" Gates, was an American Gilded Age industrialist and gambler. He was a pioneer promoter of barbed wire. He was born and raised in what is now West Chicago, Illinois. He did not enjoy farm life and began offering neighbors various business propositions at an early age, including the sale of firewood to homes and to the local railroad. When he started a local grain brokerage that failed, Gates began spending time at the local railroad station and became reacquainted with the men he previously sold firewood to. He was invited to join their poker games and through this, Gates' aptitude for cards and other games of chance was developed.

After studying penmanship, bookkeeping and business law in North Central College (by then Northwestern College), he failed as an owner of a local hardware store. Gates became interested in barbed wire and became a salesman for the Washburn-Moen Company. When he was assigned to the Texas sales territory, he learned that ranchers were adamant about not buying his product. Gates staged a demonstration of the wire in San Antonio's Military Plaza with charging cattle failing to break the barbed wire fences he had set up. He then proved very successful in selling the company's product, and went on to start his own barbed wire manufacturing business, which eventually led to the production of steel. In the process, his company was purchased by J. P. Morgan's U. S. Steel. Gates was not invited to become part of the company, and he fought back at Morgan for many years through a series of business acquisitions and sales; both men were key figures in the Panic of 1907.

Gates was the president of Republic Steel and of the Texas Company, later known as Texaco. He was instrumental in changing the steel industry's production methods from the Bessemer process to the open hearth process and in building the city of Port Arthur, Texas.