The 35-year-old, who played 10 Premier League seasons with Arsenal and Manchester City, most recently completed the second half of the 2017/18 Serie A campaign with Benevento. He made 13 appearances (10 starts), with a goal to his credit.
“I'm very happy of Bacary's arrival,” said Impact head coach Rémi Garde in a club statement. “He's a player with a great career who's still very motivated to come and help the Impact defy its end of season challenge. His personality, experience, and overall game will be a plus for our team.”
A native of Sens, France, Sagna has earned 65 caps with the French national team, including appearances at the 2010 and 2014 FIFA World Cups and Euro 2016.