Rich Campbell of the Chicago Tribune reported the transfer was finalised, with the midfielder penning a one-year deal with the Major League Soccer outfit. The player posted the following on his Twitter feed:
The MLS side have since welcomed Schweinsteiger to the club:
United confirmed the switch on their official website and included a statement from Schweinsteiger reflecting on his time at the club.
"I am sad to leave so many friends at Manchester United," he said. "But I am grateful to the club for allowing me the chance to take up the challenge at Chicago Fire.
"I have enjoyed working with the manager, the players and staff here and wish them all the best in the future. But I have to reserve special thanks to the United fans—whose support has been a very special part of my time in Manchester."
The deal sees Schweinsteiger's spell at Old Trafford end after less than two years, having been brought to the club by Louis van Gaal in the summer of 2015.
His first season at Old Trafford was punctured by injury problems, and the midfielder was unable to show his best form. Since Jose Mourinho arrived ahead of the current campaign Schweinsteiger has fallen further down the pecking order.
The former Bayern Munich man made a scattering of appearances in the United first team, although not in the Premier League.
Per Mark Ogden of ESPN, despite his reintegration into the first-team squad, it never felt as though the 32-year-old had a long-term future at Old Trafford:
Indeed, the Fire will be hoping Schweinsteiger can recapture the form that made him such a big favourite at Bayern Munich.
The German was at the hub of a team that dominated the Bundesliga, winning eight league titles as a player at the Allianz Arena. Additionally, Schweinsteiger also helped the Bavarians to the summit of European football in 2013, when they bested Borussia Dortmund to win the UEFA Champions League.
Schweinsteiger has also enjoyed success on the international stage, helping Germany become kings of international football with the World Cup title in 2014.
While injuries have taken their toll on Schweinstegier down the years, Chicago manager Veljko Paunovic will be delighted to call upon his composure and quality in the middle of the park. Additionally, for a team that have finished bottom of their conference in the last two MLS seasons, his winning mentality will be priceless.