The superstar couple attended the show Thursday night at TD Garden in Boston. Brady posted videos on his Instagram story.
The first video showed Brady pointing his camera toward the stage while singing Vertigo.
"The rumors are true, I'll be joining u2 on the remainder of the U2eiTour," Brady wrote as the caption for one of the videos.
"What time is soundcheck tonight guys," Brady asked in another video, while singing along to Pride. Gisele stood on her seat while dancing and singing during Brady's videos.
U2 is playing TD Garden again Friday before putting on shows Monday and Tuesday at Madison Square Garden in New York City.
The band performed at halftime of the Patriots' Super Bowl XXXVI win against the St. Louis Rams in 2001, Brady's first championship.