The 24-year-old versatile French midfielder interrupted a vacation in Corsica to fly to England to wrap up a six-year deal and become Alan Pardew's fourth summer acquisition.
Cabella told Sky Sports News: "For me it’s an honour and it’s an absolute pleasure to be here. I’ve had lots of support from my French coach and the French coach here.
"I’m looking forward to the support of the fans and I’m going to show what I have on the pitch. It’s going to give me great confidence having all this support behind me."
Cabella, part of the France World Cup squad but didn't feature, scored 14 league goals last season for a Montpellier team that finished three points above the relegation zone. He als ohelped Montpellier win the French league title ahead of PSG two years ago.
He will now resume his vacation and will miss the club's pre-season tour of New Zealand but cannot wait for the new season to commence.
Cabella, who can play wide on the left or right, added: "I'm a rapid player. To wear the shirt is a thing of pride. I've heard only good things about this club.
"It's an enormous club and I'm very happy and very excited to return from from my holiday."
Newcastle boss Pardew said: "Remy is a player who has been on our radar for a while and we are delighted to bring him to the club.
"He is a player who I am sure will excite our fans. He has flair, hard work and commitment, and is going to bring a talent, energy and quality to St James' Park that our supporters will enjoy.
"Remy has great ideas when the ball comes to him, and along with Siem de Jong is going to improve an area where we definitely needed some help."