Birmingham have long been linked with a move for the 26-year-old, who have also been targeted by Newcastle and Sunderland.
Birmingham manager Alex McLeish said: “We’re delighted to have David’s services. He is a classy footballer and will enhance the quality of the squad.
“He is a natural footballer capable of top delivery at set-pieces. With the likes of him, (Alexander) Hleb and (Sebastian) Larsson, who has had a great season consistency-wise, we have creative players. Bentley can provide more competition.
“He has had his moments at Spurs, but there is fierce competition for places there.
“They have a glut of superstars at Spurs. With the introduction of people like (Rafael) van der Vaart, players of that ilk, and the rise of (Aaron) Lennon, it has become very difficult for him. The quality is amazing and maybe he can get his career back on track here.”
A statement on Birmingham’s official website read: “Blues have secured the services of Spurs and England winger David Bentley on loan until the end of the season.
“Subject to his registration being accepted by the Football Association and Premier League, Bentley will be available for selection in Sunday’s fixture at home to Aston Villa.”
