Managing director Derek Llambias told the club's official website: "If you look at clubs like Manchester United and Arsenal, Sir Alex Ferguson and Arsene Wenger have shown that stability gives you the best platform to achieve success, and that is the model we wish to emulate here.
"We're looking to build on the success we had last season and these new contracts are aimed at keeping the club progressing on and off the pitch, as we have done since returning to the Premier League in 2010.
"Alan has done a fantastic job over the last couple of years and has proved what a great Premier League manager he is. I have total respect for him in all football matters and have an excellent relationship with him which I think benefits the club enormously."
Newcastle narrowly missed out on a Champions League spot last season and the North East side currently sit 10th in the Premier League table.