The striker has backed the young forward to have a big future at the Stadium of Light.
The youngster has broken into the Black Cats' first team squad in recent weeks after starring for the Under-21 side.
Watmore made a starring appearance in the win over Crystal Palace at Selhurst Park in the Premier League on Monday night, coming off the bench and helping his side to all three points.
The 21-year-old has also starred on the international stage, putting in a top display for the England U21s with a goal and two assists in a 15-minute cameo.
Defoe believes he has a bright future ahead of him in the game.
“Dunc is brilliant and so athletic, quick, direct and confident,” he told safc.com.
“He’s a young lad and I’m delighted for him because I remember when I was in that situation – all he just wants to do is play football."
“He’s a bright lad, a nice boy and he’s going to do really well for this football club. He’s the future.”
Given how well Watmore has performed for Sunderland when given the chance, there is naturally now a desire to see him starting games.
Sam Allardyce’s slow approach is probably for the best however, with young players unpredictable and Sunderland’s current situation a risky one at best.
Watmore could have a big say in where they finish this season though, especially if he performs as he did against the highflying Eagles.
And if he does continue to shine like that, Allardyce may have little choice but to select him in future.