Tennant is the son of Essdale Helen and Alexader "Sandy" Mc Donald. His brother Blair and his sister Karen grew up with David Tennant. David Tennant was three years old when he told his parents he wanted to be an actor because he was a big fan of Dr Who. But his parents didn't think it was a good idea.Tennant's talent was discovered by the actress Edith Arthur. She told Tennant's parents that he had talent.