The former Kenton School pupil played more minutes than anybody else during the Magpies' Sky Bet Championship title-winning campaign, and was wearing the captain's armband by the final whistle on Sunday.
The left-back has been with Newcastle since the age of nine and told nufc.co.uk: "When you're growing up, lifting a trophy for the team you support is something you always want to do.
"For it to happen in the way it did made it even more special and even now, nearly a week on, it's still sinking in. The roar from the fans when Aston Villa scored is something I'll never forget."
Dummett won the Scottish League Cup at Hampden Park during a loan spell with St. Mirren in 2013 and has now made more than 100 league appearances for Newcastle.
He added: "When we went down, I was determined to help the club get back to the Premier League and as a team, we did that.
"Promotion was the main goal, but to achieve it as champions was even better and the medal and the memories are something we'll always be able to cherish.
"It was a long, hard season and every player contributed massively. We'll go away now, get a holiday and recharge our batteries and then make sure we come back in July ready for the Premier League."