Born and raised in Ireland, the 26-year-old was part of Munster’s Under-20’s squad before relocating to the USA to further his studies.
Earning a Bachelor’s Degree in Marine Engineering Technology and a Masters in Marine Resources Management in Texas, Mullen represented USA Under-20s in the Junior World Trophy back in 2011.
Making his full international debut this summer, the 122kg prop started in the USA’s victories over Canada, Scotland and Russia, and has been playing his club rugby for Major League side Houston SaberCats.
Speaking after completing his move to Kingston Park, Mullen said: “I am delighted to be joining Newcastle and am looking forward to developing my game further alongside a great squad.”
Falcons director of rugby Dean Richards said: “Paul has broken through to the full international scene in quite a big way over the past few months, and been part of a rapidly-improving American Eagles side.
“His presence will further bolster our front-row resources going into the new Gallagher Premiership season as we look to improve yet again on what was our best league finish for 20 years.”
Mullen’s arrival comes on the back of the previously-announced signings of George McGuigan (Leicester Tigers), Pedro Bettencourt (Carcassonne), Logovi’i Mulipola (Leicester Tigers), Guy Graham (Hawick), Tom Arscott (Rouen), Connor Collett (North Harbour), Nemani Nagusa (Aurillac) and Johnny Williams (London Irish), as well as senior academy promotions for England Under-18s stars Cameron Nordli-Kelemeti, Morgan Passman, Will Montgomery, Tom Marshall, Josh Hodge and Rob Farrar.