NASCAR O'Reilly Auto Parts Series

The NASCAR O'Reilly Auto Parts Series (NOAPS) is a stock car racing series organized by NASCAR. It is the company's second national division, behind the NASCAR Cup Series and in front of NASCAR Craftsman Truck Series. NOAPS events are frequently held as a support race on the day prior to a Cup Series event scheduled for that weekend.

The series was previously called the Budweiser Late Model Sportsman Series in 1982 and 1983, the NASCAR Busch Grand National Series from 1984 through 2002, the NASCAR Busch Series from 2003 through 2007, the NASCAR Nationwide Series from 2008 through 2014, and the NASCAR Xfinity Series from 2015 to 2025. Under the Xfinity name, it was sponsored by Comcast via its consumer cable and wireless brand. O'Reilly Auto Parts assumed title sponsorship in 2026.