I think Emil Chuck, the Dean of Case, once said that the dean's list doesn't really say much in an awards section because your transcript speaks for itself. A student is bound to be awarded Dean's List for a high GPA. But regarding your question, I'd group them together if you have other awards to input.
If you've already graduated with that recognition, then definitely.
The awards section is difficult to fill up for most applicants, so try to put whatever you can in there if you were ever awarded something from your school or a club. Some schools may see that you made the Dean's list or graduated with some kind of honors and brush past it since they already saw your GPA, but it definitely cannot hurt.