The 36-year-old centre was released by Bridgend at the end of last season but claims he is joining a club that has the potential to regain its place at the peak of Welsh rugby.
Devereux, capped by Wales and Great Britain at rugby league, will join the first division club who narrowly missed out on top spot last season.
“I had offers from a few Premier Division clubs but I am excited by what Bob is attempting to do at Pontypool Park,” he said.
“They have the potential to be a big club. They are a sleeping giant but have been stirring and are ready to reawaken.
“If you ask anybody in the rugby world to name famous Welsh clubs Pontypool would be one of the first you would hear.
“It is like Widnes, for whom I played rugby. They had a spell in the doldrums but people were still talking about them alongside the likes of Leeds and Wigan.
“Pontypool are a First Division club but they have Premier ambitions that are second to none.
“I believe they are the one club who could get promoted and stay there. I want to be part of that promotion drive, playing alongside people like Mark Jones and Bryon Hayward.”
