1. His real name is David John McDonald.
2. His father was a Presbyterian minister.
3. He is married to the actor that played his daughter in the show, Doctor Who, who was also the 5th Doctor’s daughter. Making for all kinds of weirdness on the mixture of reality and fantasy in that family tree line.
4. Second Scottish actor to be cast as the Doctor, the other being Sylvester McCoy. (And now of course, Capaldi).
5. He is consistently voted favorite Doctor.
6. Played Barty Crouch Jr. in Harry Potter and the Goblet of Fire.
7. He picked his stage name because his name was already taken, and named it after frontman for The Pet Shop Boys, musician Neil Tennant.
8. He is a voice in How to Train Your Dragon.
9. Currently in an American show called Grace Point, (pretty much a replica of Broadchurch).
10. Here is a bit of Catherine Tate and David Tennant.