American Apparel was founded in 1989 by Dov Charney, who had a long history with t-shirts and a fascination with American culture.

It was during Charney's freshman year at Tufts University that the company took on the name "American Apparel" and began to experiment with screenprinting, importation and other parts of the apparel business. In 1997 after a variety of iterations, including a period of manufacturing in South Carolina, the company moved to Los Angeles. Charney began to sub-contract sewing with Sam Lim who, at the time, had a shop with 50 workers under the Interstate 10 freeway in east LA. Months later the two became partners. In 2000 American Apparel moved into its current factory in downtown Los Angeles where it continued to grow primarily as a wholesale business, selling blank t-shirts to screenprinters, uniform companies and fashion brands.

After its success as a wholesale brand, the company moved into the retail market. The company was ranked 308th in Inc.'s 2005 list of the 500 fastest growing companies in the United States, with a 440% three-year growth and revenues in 2005 of over US$ 211 million.

In late 2006 American Apparel announced a reverse merger, in which Endeavor Acquisition Corp., a special-purpose acquisition company founded in July 2005, bought the company for $360 million. The merger closed in December 2007, at which point American Apparel became a publicly traded company. As a result, Charney became the President and Chief Executive Officer of the publicly traded company known as American Apparel, Inc. He remained the majority shareholder.