The youngster is Matt Taylor's ninth signing of the Summer
Smerdon, who progressed from West Brom's youth academy, says he's delighted to join the Grecians.
"It’s a really good opportunity here at Exeter," he said. "There are some high-profile names to have come through like Ethan Ampadu and many others.”
Speaking about his latest signing, Grecians manager Matt Taylor added: “We’ve tried our best in terms of recruiting in the right areas, Noah is someone who has been on our radar for some months now. We’ve watched him several times and we’ve got good reports from various managers who he has worked under at Gloucester in Marc Richards and Mike Cook, now.
“He’s a player with huge potential and hopefully this is the right club for him to develop that potential and become a first team player.”