The actor and Debra Messing, who plays Grace on the fan- favourite comedy, took to their respective Instagram accounts to share photos of them together on the set, reported Ace Showbiz.
Debra shared a photo and wrote, "Time to swoon. Yup! He's back. That southern gentleman that stole all of our hearts- @harryconnickjr. There will never be another Leo. @nbcwillandgrace."
Harry also posted a photograph with the actor.
Leo's return is somehow surprising since it was previously reported that the new reboot would ignore the show's final episode, in which Grace was married to Leo.