The 30-year-old left-back, who can also operate at centre-back, made his first team debut for the Magpies in January 2013 and has amassed more than 200 appearances for the club.
Born in Newcastle, Dummett joined United’s Academy aged eight and progressed through the ranks, eventually captaining the club’s Under-21 side and enjoying loan spells with Gateshead and St Mirren – winning the Scottish League Cup with The Buddies.
Dummett has also represented Wales on the international stage, qualifying through his grandfather. He made five Under-21 appearances before earning four full international caps.
Dummett said: “This is a hugely exciting time for the football club and the city so I’m delighted to be committing another year here and staying at my boyhood club.
“I’m immensely proud that next season will be my tenth involved with the first team and I’m really looking forward to being part of what is a big season to come. Howay the lads!”
Newcastle United Head Coach, Eddie Howe, said: “Paul is a consummate professional who has given so much to this club and I’m delighted he will be staying with us.
“He is a player and a person I like very much. He leads by example both in the dressing room and on the pitch and I’m pleased to retain someone with his positive influence and defensive capabilities."