Like so many top athletes and A-list celebrities before him, the former NFL quarterback came to see the American superstar performing at Bercy Arena.
Biles could have tied the record for most Olympic gold medals by any female athlete in any sport with two more wins on the final day of gymnastics competitions, but she fell during her beam routine on Monday.
She will later put an end to her Parisian campaign on the floor exercise, as she chases an eighth Olympic gold medal.
Brady attended the beam competition with his daughter, Vivian, sitting close to the front row. He also met with Biles' teammate Sunisa Lee, who posted a picture of her posing with Brady on her Instagram account.
The large number of celebrities who have turned out at the gymnastics venue sometimes gave the impression that the Cannes film festival was going on at the Bercy Arena.
A-listers Nicole Kidman, Natalie Portman and Serena Williams previously gathered at the Olympic venue to watch the most decorated athlete in the history of gymnastics. Spike Lee, Michael Phelps, Lady Gaga, Tom Cruise and Jessica Chastain also made a stop at the gymnastics venue.