1. "The Impossible Astronaut" was the first episode actually filmed in the US.
2. "Rose" was the first episode named after a companion.
3. Peter Capaldi was called in to audition for the eighth Doctor, but chickened out because he didn't think he'd get it.
4. The show almost ended after David Tennant's departure
5. The weeping angels are based on the game, What's The Time, Mr. Wolf!
6. The eleventh Doctor's outfit was almost buccaneer pirate-style.
7. The original pilot episode, which was thought to be lost forever, was rediscovered in 1978 in a mislabelled film can.
8. Asteroid 3325, a main belt asteroid discovered in 1984, is named TARDIS after the Doctor's time/space machine!
9. Matt Smith was the youngest Doctor so far. (Obviously!)
10. Jamie McCrimmon, companion, appeared in 116 episodes of Doctor Who!
11. The words "TARDIS" and "Dalek" became so familiar to British audiences that they were added to the Oxford English Dictionary.
12. Caitlin Blackwood, who played the young Amelia Pond, is Karen Gillan's real life cousin. The first time they met was at an on set read-through, as Caitlin was born in Northern Ireland and Karen in Scotland.
13. In case you didn't notice, I did 12 facts because there are 12 Doctors, and this one because I know that some of you out there will be like "but what about John Hurt..." So yeah.
Suggested by bestieolive7 !
Also the next one will probably be Once Upon A Time, so stay tuned!