Yes. Skunks are not as easy to litter train as a cat, but they can be trained to use a litter box. Here are a few pointers that will help you to get your pet using the restroom like you want:
Skunks prefer to back into a corner to use the restroom, so a corner litterbox will often make them more comfortable (and keep poop off your walls).
Skunks are often particular about the substrate in their litterbox. If your skunk is using the restroom right next to the litterbox, or napping in the litterbox instead of pooping, try changing the litter to a different type. I have used corncob litters, newspaper, puppy pads, and pine litter all with success.
Do not use chemically treated litters, clumping litters, or litters with "crystals" in them. Skunks like to wipe their bums on the ground after using the restroom. All the aforementioned litters have ingredients that do not do well if a piece of the litter is caught in their backside during this process.