[Scooter]

[color=#000000ost_uid0][quoteost_uid0="Zeke"]Hang on... the guy [iost_uid0]is[/iost_uid0] actually called Doctor Who, right? Â I know he's usually just The Doctor, but does anyone call him Doctor Who? Â [/quoteost_uid0]
What SCMoll said about the credits and so on is true; there's ambiguity there. But if you go by what is said on screen, it is clear that he is called The Doctor, and that Doctor Who describes rather the enigmatic nature of his character.

The Doctor, however, is itself clearly a nickname (he refers to himself being "called" The Doctor and talks about the honorary nature of his "doctorate", etc.). We do not know The Doctor's real name (enigma again). Even on his home planet of Gallifrey they call him The Doctor. Similarly, the Doctor's nemesis only "likes to be known as The Master"; his realy name, too, is unknown, and the Time Lords call him The Master like everyone else.

The dialog that fixes all of this is in the very first episode, where Ian, meeting Susan Foreman's professorial grandfather, addresses him as "Doctor Foreman." The Doctor replies, "Doctor who? Who?" Some even say that he was not known as The Doctor at all until Ian first addressed him that way!

There are a handful of near-exceptions, including the "Doctor Who?" "Exactly" exchange alluded to above; the Second Doctor once refers to himself as "Doctor von Wer" when in disguise as a German; and most notoriously, a villian says "Doctor Who must be destroyed" in one late First Doctor episode. These are aberrations from the dogma that his name is The Doctor, not Doctor Who. (It's the same kind of discrepancy as Kirk's tombstone reading "James R. Kirk" in "Where No Man Has Gone Before.")

Personally I think this is only relevant, however, if you find yourself actually standing in the TARDIS and physically addressing the Doctor, or talking to K-9 about him. It is quite acceptable for us, in the real world, to refer to the fictional character as "Doctor Who"--at least outside the presence of the most truly rabid fan. After all, it's clearer, as SCMoll noted, and that's why BBC publicity uses it (for outsiders; if you go to the cult site at BBCi a lot of material refers to The Doctor).

There. Much more discourse than you needed to know. I am available at reasonable rates for lectures, parties, and bar mitzvahs.

PS All of this ignores the two [iost_uid0]movies[/iost_uid0] made in the 60s with Peter Cushing. In those films Cushing played an Earthling scientist [iost_uid0]named[/iost_uid0] "Doctor Who." How's that for adding confusion to the mix> [/colorost_uid0]