"The offense and passing games under Josh's direction have achieved at a very high level throughout his coaching career," Michigan coach Jim Harbaugh said via statement. "Josh will provide leadership to our offense while being a great mentor to our student-athletes and an outstanding addition to our coaching staff."
Gattis, 34, has specialized in coaching wide receivers during his first nine years of coaching at the college level.
"It is an honor and a privilege to join the University of Michigan football family under Coach Harbaugh, one of the most successful head coaches in all of football," Gattis said in a statement. "I am deeply humbled by the opportunity to serve as your offensive coordinator. This is the leadership challenge I've coveted. The football tradition at the University of Michigan is among the very best in college athletics. My family and I couldn't be more excited to arrive in Ann Arbor."
Michigan did not have a coach with the title of offensive coordinator on staff last season. Pep Hamilton, listed as an assistant head coach and passing-game coordinator, played a big role in the Wolverines' offense and is still a member of the coaching staff. Gattis fills a vacancy left by Jim McElwain, who took the head-coaching job at Central Michigan after one year with the program.
Gattis coached at Penn State, Vanderbilt and Western Michigan before spending the 2018 season with Alabama.