Tennant, who will become the 10th Time Lord of the British TV series "Doctor Who," is taking over from Christopher Eccleston, who quit after performing for one season, the BBC reported Saturday.
"I grew up loving 'Doctor Who' and it has been a lifelong dream to get my very own Tardis," said Tennant. "Taking over from Chris is a daunting prospect -- he has done a fantastic job of reinventing the doctor for a new generation and is a very tough act to follow."
Tennant has also starred in BBC shows "Blackpool" and "He Knew He Was Right," and the movie "Bright Young Things."
A new 13-part "Dr. Who" adventure and Christmas special will begin filming later in 2005.