The 26-year-old wing has made just two starts for the Falcons this season and is hoping to relaunch his career in France.
Falcons director of rugby, Steve Bates, said: "Ollie's attitude has always been outstanding, and he leaves the club with our best wishes."
He added: "Unfortunately his appearances for us have been limited this season, but despite that he has always remained a positive presence around the camp, and I am sure he will seize his new chance in Paris with both hands."
Tom Biggs and Charlie Amesbury have agreed to join Newcastle for next season while England rugby league international Danny Williams will switch codes, leaving Bates confident the squad will have enough quality in wide positions.
He added: "Our wing contingent is shaping up nicely for next season, with plenty of quality out wide.
"Both Tom and Charlie will add a big attacking threat, and we hope for Danny to continue the superb form he has shown throughout what was only his first ever season in rugby union."