Founded in 1957 by the O’Reilly family, O'Reilly auto parts operates more than 6,000 stores in 48 states, Puerto Rico and Mexico.

By 1932, he had become manager of Link Motor Supply in Springfield, and one of his sons, Charles H. (Chub) O’Reilly, joined the company.

[6][4] On April 23, 1993, O'Reilly completed an initial public stock offering, and since then trades on the NASDAQ market under the symbol ORLY.

On October 1, 2001, O'Reilly purchased Mid-State Automotive Distributors, Inc., adding 82 additional auto parts stores in seven states, as well as two distribution centers.

[citation needed] On July 11, 2008, O'Reilly completed the largest acquisition in its history with the purchase of CSK Auto, adding 1,273 stores in 12 states.

In August 2016, O'Reilly entered the Pittsburgh market with the acquisition of the five-store Frank's Auto Supermarket chain.

On October 26, 2016, O'Reilly announced that it was acquiring Bond Auto Parts, a 51-store chain headquartered in Vermont with locations in New Hampshire, Massachusetts, and New York as well.

[11] On November 13, 2018, O'Reilly announced that it was acquiring Florida-based Bennett Auto Supply, a 33-store chain headquartered in Pompano Beach.

On December 18, 2023, O'Reilly Auto announced it was acquiring Groupe Del Vasto, which does business as Vast-Auto and is headquartered in Montreal, Canada.