The NFL legend, who stopped playing in February, has “entered into a partnership” with Knighthead Capital Management LLC, the new owners of the Blues.
The 46-year-old will be in charge of St. Andrew’s new advisory board.
“Tom Brady’s decision to join the Birmingham City team sends a clear message. “World-class is the standard we set,” said Knighthead co-founder Tom Wagner.
“Tom is both spending money and giving a lot of his time and knowledge.
“Tom will have a direct effect on the club as chair of the advisory board. The men’s, women’s, and youth teams will all learn from what he knows.
“Tom’s goal is for Birmingham City to be seen as a leader in the world of football when it comes to nutrition, health, wellness, and recovery.”
The club also said that Brady would work closely with the board and the management team to help with global marketing efforts and to find new business partnerships.
In the past few months, a number of big American stars have made small investments in English football teams.
JJ Watt, a former NFL defensive end, bought shares in Burnley in May, and Michael B. Jordan, an actor and director, bought shares in Bournemouth at the end of last year.
Jordan Spieth, Justin Thomas, and NBA All-Star Russell Westbrook are also partial owners of Leeds United.
In 2021, LeBron James, another NBA star, will become a small partner in Fenway Sports Group (FSG), the company that owns Liverpool.