david tennant (tenth doctor) is Scottish
David Tennant is, therefore, British. Only British actors have so far played the Doctor. It's impossible to say that the programme makers will never in the future cast a non-British actor, because we can't predict the future.
- There is no hard and fast rule that says only British actors have to play the Doctor - for the 1996 TV movie which was co-produced by Universal and Fox TV a number of non-Brits were considered such as Canadian Donald Sutherland, for example - however as long as the BBC produces the series by itself, and the BBC continues to operate under a taxpayer-support model (in the UK residents are required to pay a so-called "licence fee" (tax) on televisions and radios that go to pay for the BBC) from a political standpoint they will never cast someone who is not British as the Doctor. If the BBC ever drops the series and another network picks it up, whether that be ITV or BBC America (which is a different company than the BBC itself), then its doubtful such a prohibition would remain.