"Answer to my question" or "answer on my question"?

What's the right usage: an answer to my question or on my question?


"To" is right; "on" would be intelligible, but not the usual way to say it: it would mean "an answer on the subject of my question", which is needlessly long and less clear, except perhaps in unusual contexts. You would use "on" in sentences where you could use "about" with the same meaning: "I read his answer on food processing, and it was rather interesting". "Food processing" is the general subject of the answer, and so probably of the question as well – it is not the question itself.