Art History - What do I have to do to become an art history professor?

What do I have to do to become an art history professor?

I'm currently taking an art history class, and I really enjoy it. Is it hard to become one and will need a PhD to be a professor?

Most universities would require a masters at the least, you'd have more options with a phd however. A degree in teaching couldn't hurt as well.
To teach Art History in 2yr colleges a Masters degree with at least 18 credits in A.H is usually required. 4yr colleges will sometimes hire a person with a masters but for full time tenure positions a PhD is required. A PhD really equals job security. Please note that there are fewer and fewer full time tenure positions now, so competition is tough! Also you will need proficiency in a foreign language for your masters in AH. Good luck!