Will this work on a square pole or column?

Yes, this product will fit square posts too because it is half inch wide wood panels on a flexible backing. A standard 4 inch square post is actually 3-1/2 inches on each side. For this you would start with the 16 inch wide size Pole-Wrap and cut it down to 14 inches (3-1/2 x 4). Use a utility knife between the panels. Cut the standard 8 foot length with a fine tooth saw as needed. What looks really nice is that you can finish the top and bottom with regular striaght crown and base moulding. Use a miter box saw and cut at 45 degrees for each corner like a picture frame.

This pole cover is designed to fit poles that are 3 to 3.5 inches in diameter. If the length and width of your square-shaped pole is between 3 to 3.5 inches, this cover will fit, though it may have trouble wrapping around the corners. Otherwise, you could put multiple covers together to wrap your pole.