Chad A. Johnston is an American NASCAR crew chief who works for Legacy Motor Club for their No.

Johnston was Truex's engineer prior to his promotion by MWR to crew chief midway through the 2011 season.

Larson would win 3 more times throughout the season, finishing 8th in the championship standings after having a lack of consistency in the playoffs.

[5] In 2020, Johnston would become the crew chief for Matt Kenseth after Kyle Larson was suspended for saying a racial slur during a streamed iRacing event.

[6] In December 2022, Johnston returned to Stewart—Haas Racing and the NASCAR Cup Series after it was announced that driver, Ryan Preece would replace Cole Custer in the No.

Johnston and Preece previously worked together in the Truck Series with David Gilliland Racing, having won together twice, at Nashville Superspeedway in 2021 and 2022.

When SHR closed down after the 2024 season, Johnston was hired by Legacy Motor Club days after the 2024 season-finale at Phoenix to be the team's Manager of Race Engineering.

[8] After graduating college at Indiana State University in 2004, Johnston got a job as an engineer for Morgan-Dollar Motorsports in the NASCAR Camping World Truck Series.

[10] With one race to go in the 2020 ARCA Menards Series West season, Johnston was picked up by DGR-Crosley to crew chief their No.