Can I lay ceramic tile over ceramic tile?

I don't recommend placing ceramic tile over ceramic tile. I know it's a lot more work to remove the previous tile, but worth it in the end.

Are you talking floor or wall tile? Either one should not be done.

You have to break up and remove the old tile and grout. Only then can you retile.

I wouldn't recommend it. It will be extremely heavy because you will need to put cement board so that mean 2 layers of board plus 2 layers of tile. It's best to remove.

I know there are some people who have done it, but as others here are saying, I wouldn't do it! It is a lot of work removing the old tile and replacing it, but there are a lot of little things you may not realize at the time, like the new tile will be taller than the old tile it is meeting up with, there will be a lip. If you are replacing the whole house going over old tile, the front, back and any other exterior doors will have to be changed to accept the higher flooring and so on! Plus, it may seem easier now but the next time you want to change the flooring out, it's double the work, because you cannot just break up one layer of tile, the bottom layer will break up as well and now you have to remove it all anyway! Hope this helps!