Nathaniel McMillan is an American basketball coach and former player who previously served as head coach of the Atlanta Hawks of the National Basketball Association (NBA). He coached the Seattle SuperSonics from 2000 to 2005, the Portland Trail Blazers from 2005 to 2012, and the Indiana Pacers from 2016 to 2020. He spent his entire 12-year NBA playing career with the SuperSonics, then served as an assistant coach for one-and-a-half years and as head coach for almost five years. His long tenure as a player and coach in Seattle earned him the nickname "Mr. Sonic".

The Seattle SuperSonics were an American professional basketball team based in Seattle. The SuperSonics competed in the National Basketball Association (NBA) as a member of the Western Division (1967–1970), and later as a member of the Western Conference's Pacific (1970–2004) and Northwest (2004–2008) divisions. After the 2007–08 season ended, the team relocated to Oklahoma City, where they now play as the Oklahoma City Thunder.