Waltrip said Wednesday the hiring allows Bobby Kennedy, who has worked in several roles for Waltrip the past two seasons, to move into a management role.
"Our organization continues to grow and add depth in several key areas," Waltrip said in a statement. "Bringing Bootie on as my crew chief is part of a larger plan that enables Bobby Kennedy to move into a critical management position. We have discussed this move since the summer, but waited until we were able to hire a crew chief of Bootie's caliber and we're really glad to have him join MWR."
Barker, who works for Haas CNC Racing, has worked for Bill Davis Racing and Hendrick Motorsports. Stewart will own 50 percent of Haas next season, and the team will be called Stewart-Haas Racing.
Barker became a crew chief for Scott Wimmer in the Nationwide Series, winning four races in 2002. He's spent the past five years as a Cup crew chief for Dave Blaney, Jason Leffler, Mike Bliss, Jeff Green and Scott Riggs.
"I really appreciate the confidence that Michael has in me," Barker said. "He has accomplished a lot in his racing career and the fact that he wanted me to be his crew chief goes a long way for me personally."