The club made the shock announcement on Wednesday morning.
The news comes a day after reports linked the defender with a move to Tottenham Hotspur and Chelsea, who may now both have to seek alternative transfer targets in January if they were indeed interested in the Englishman.
The captain is arguably the club’s most important player alongside Jonjo Shelvey, and has enjoyed a great stint as club skipper since being handed the armband by Rafa Benitez in August 2016.
He helped guide the team out of the Championship in 2016.
He then played a huge role in Newcastle’s impressive 10th-placed finish last term.
Things have been difficult in 2018/19, with the whole team struggling. Lascelles has by no means been the worst of the bunch though.
Surprise deal could provide major psychological boost
This news is fairly out of the blue and has stunned a lot of downbeat Newcastle fans.
The fact that it is a six-year deal is quite a shock, and will mean that the ball will be firmly in the Magpies’ court should they wish to sell the player in future transfer windows.
At the moment though, that notion will be out of the question.
Lascelles staying put despite reported interest from Spurs and Chelsea is a huge boost for the club.
Many anticipated that he might leave in January or next summer, but that now seems very unlikely.
If Newcastle cashed in on Lascelles in January, then it would probably condemn them to the Championship.
With the team struggling to score goals, Benitez has needed his captain to keep things tight at the back.
They’ll need his influence at the back for what is shaping up to be a very difficult season. News of his new deal is sure to raise spirits in the dressing room.