Are there galaxies with 2 or more super massive black holes orbiting each other? We now know that most stellar systems have 2 or more stars orbiting each other. Do we know of any galaxies which have 2 or more super massive black holes orbiting each other? Is it possible?
Yes, there are galaxies with two supermassive black holes in the center, see for instance 4C +37.11

Most likely such galaxies are formed by collision and merger of two galaxies, and their cores have not yet merged. Source