i was just wondering if it was possible to make a hidden compartment in a school locker, to hide things, like, chemicals, drugs, weapons, and shit like that and if so, then how would you do it?

It depends on the type of locker, but yeah, there's probably room for secret compartments, however if you stash drugs in there and they bring in dogs, they'll tear your locker apart looking for them.

ya, my schools only done that once, and that was before i went there lol

Go to the locker room and find an unocupied locker and put a lock on it and store it there. Then if they come in with the dogs and find it they won't know who's locker it is.

our school is to poor to afford a locker room, we have lockers down the hallways, but it could still work, the only problem is that they give you locks to put on there, and if you bring your own, they just cut it off

http://www.empirewest.com/ceilingtiles/mineralFiberTilesSprinklers.jpg
Many schools have the pictured ceiling.
A good place to hide things would be above the ceiling; the tiles are movable. Might be a hassle to get at it though. If you have trouble reaching the ceiling you could go to the washroom and stand on the toilet.

Back in high school we often used to duct tape things to the top of our lockers. For some odd reason, we always got away with it.

Duct tape to the top should work, just make sure you have a bottom locker (assuming you have a set of lockers ontop and one on bottom). Then from any normal person's field of view, they can't see whatever it is. Or the roof tiles, that is probably the easiest. Personally, I have no trouble reaching them with the help of a chair being tall.

This.

Do what everyone else has been saying unless you are planning on bringing in some power tools.