How many professors are there at Oxford University?

Very hard to answer, even with a copy of the University Calendar in front of one. The number actually teaching is a lot less than the number that exist.

ox.ac.uk gives some facts and figures but nothing like a final figure. Each college will have its own staff in each field it teaches (not all colleges teach all subjects) and not all of them will be Professors in the English sense of the word.

www.ox.ac.uk and a a search under staff will give you the information if you would like to count.

Mibmob, that's not going to be an accurate figure even if you go through the whole lot - for instance, my husband is still listed under his old job title (a teaching position) even though he hasn't done it since 2000. He now works exclusively in research. When working at the Bodleian I had to count all the staff employed by the University Libraries, and it's like the Rollright Stones - every time you count you get a different answer. Trust me.

(FWIW the figure for the Bodleian is ~550, and for the entire University Libraries Service it's more like ~2000. Some of these people teach and some don't...)