Some people have luck hanging the paper so it rolls from underneath, this didn't work for us they figured it out.
We haven't had paper on the roll since we got cats.
If you are insistent on keeping your toilet paper on a roll hanging near the toilet instead of a sealed container near the toilet, make yourself a toilet-paper cover.
Get a pair of hinges from a hardware store, a small plastic bin big enough to cover your toilet paper holder, and your tools.
Screw one end of the hinges to the wall above your toilet paper holder, and the other to the plastic bin. I suggest using nuts and bolts and a hole punch for the plastic bin end of the hinge.
What you should end up with would be a plastic bin that covers your toilet paper holder and swings up when you want to get at the paper.
Some cats should figure this out, but constantly having the cover swing back over their paws should discourage them.
Another possible design would be the same plastic bin, with one side cut away, screwed to the wall and covering the toilet paper on the sides and bottom so that one can reach into the top, where the cut-out side is. Of course the cat can technically still get at this, but the only way is to stand on the (very thin) edges of the plastic bin, or to stand on the (unstable) roll itself. Should discourage Kitty, but looks weirder than a cover. This is dependent on whether or not the cat can reach the roll while standing on the toilet, and hook the paper out.
It's funny the first few times it happens, but after that it gets a little old... LOL
Paper towel rolls are another favourite of one of my girls. She'll wrap herself around it and attempt to "gut" it with her back legs. Now that's a mess!
We have a heat register right under the TP (I cannot tell you how annoying that is) My husband taught me to tuck the end of the TP into the roll so that the breeze from the heat register cannot unroll it. One evening, I forgot to do this (shortly after we adopted our kitty Marcie) the breeze from the register was fluttering the end of the paper and Marcie thought that it would be great fun to unroll it. My husband went down to the bathroom at 3am to find a trail of TP all the way to the kitchen and a guilty looking cat. She leaves it alone if the end is tucked in.
Thanks so much. Just keeping it out of the way is working but im thinking now about the cover. We cannot keep the bathroom shut because thats where the kitty litter and food and water is. We live in a apartment so there isn't many choses on where to put that stuff.
My other kitten was never into the toilet paper. She just ignored it so we always let it be but then we got a new kitten and thats when it started to happen.
I wish my kitten would go for the toilet paper! Instead he discovered the bathroom wallpaper and is peeling that off. And one day I saw him spot a mark on the hallway wall that he must have thought was a bug and that's about a 3inch hole in the drywall now.