O'Reilly Automotive, Inc. (O'Reilly Auto Parts) is one of the largest specialty retailers of automotive aftermarket parts, tools, supplies, equipment and accessories in the United States. Founded in Springfield, Missouri in 1957, it serves both do-it-yourself consumers and professional service-provider customers through a dual-market strategy backed by a dense distribution and hub-store network. As of 30 June 2026 it operated 6,695 stores across 48 US states, Puerto Rico, Mexico and Canada, with roughly 94,000 team members.