Do I call my supervisor “dean” or “professor”? My supervisor is the dean of an engineering department at my university. Should I address him as Dean Smith or Professor Smith? Personally, dean sounds a little clunky for me talking to my faculty supervisor but I’ve been using it so far, and he hasn’t really mentioned anything about it.

Is it normal to address someone as dean or should I start using professor instead?

Also, I don’t know if he’s the type to care about such things.
If you don't want to ask him directly (the easy solution), you could always ask other students what they do.  In general, I would stick to "Professor Smith."  People don't have be called by their full titles (I would never want or expect to be called "Associate Professor Webster").