"I would like to thank everybody for their welcome, and for inviting me to sign for the Club," said Cisse.
"It is an honour to play for such a big club and I am looking forward to it.
"I want to pay back the confidence the Club have shown in me, and give the supporters something to be proud of.
"I am aware of the huge importance of the number nine shirt, and when I spoke with the manager he made it very clear how important this shirt is.
"I will treat it with the respect and I hope to do my very best in this shirt."
Managing Director Derek Llambias added: "We are very pleased to bring Papiss to the Club.
"It is a signing which perfectly complements the type of side Alan is building, and we are sure he will prove to be an excellent acquisition going forward.
"He has travelled a long way to come and sign with us today, and we thank the Senegalese Football Federation for their assistance in helping us secure the player."
Newcastle United manager Alan Pardew said: "Ever since Andy Carroll left, Papiss was my first choice in the specific role he has at the end of the play.
"He is a finisher with an already-established CV in the Bundesliga, where we have monitored him for the best part of two years.
"Unfortunately he was out of reach, financially, for us in the summer, but it recently became apparent that Derek Llambias and Lee Charnley could do the deal in this window.
"It has become obvious this season that the team and the Club have done exceptionally well, and Mike Ashley has backed me to bring this player to the Club.
"I would like to thank Mike, Derek and everyone involved for getting this deal over the line.
"I spoke to Demba about Papiss, and he cannot wait to join up with his teammate in Newcastle.
"In the short-term, of course, he is at the Africa Cup of Nations, but the competition he will bring to our squad when he joins up with us should inspire the players and reassure them of this Club's ambition.
"Our fans know that this shirt brings its own pressures. One of the iconic numbers in world football - the number nine of Newcastle.
"It will be only fair that Papiss is given time to understand the responsibility it brings.
"As the manager, I wish him all the luck in the world to bring success to himself and this Club."
