Spurs sit third on the league table, seven points behind leaders Manchester City with a game in hand, and after a recent run of nine wins from their last 10 outings, Defoe can see them battling for a higher finish.
"The manager thinks we can win the Premier League and I canâ€™t see why not," he told talkSPORT.
"Weâ€™ve got a winning mentality and a belief that it doesnâ€™t matter who we play, we can win.
"The squad is unbelievable. Weâ€™ve got two good teams who can compete in the Premier League. When we play like we can, when we pass quickly and break with intensity, it must be brilliant to watch.
"We've got a winning mentality and a belief that it doesnâ€™t matter who we play, we can win. Everyone is buzzing in training and the lads believe we can go on do well.
"We'll just take each game as it comes, keep winning and see where we end up at the end of the season."