Some say Atlantis was a continent on Atlantic Ocean and it sank. No, we can't have that on earth, it's just to large to disappear.
But it can be some kind of ancient island city in, say, Mediterranean that blew up in some volcanic disaster or earthquake. As far as I know the only real source of the Atlantis myth is a chapter of a book written by an ancient Greek philosopher. There are many myths about lost civilizations of past golden ages and Atlantis is just one of them.
So, my answer is: It is possible but it probably did not exist.