With the provisional cast on, yes. However I have done this with a standard cast on by just picking up one leg of the cast on stitch.
My husband does have a complaint about this though - the seam is so tidy he can't tell front from back! :lol:
On the ladies hats I made I crocheted a small flower to put on the front & on the mens ones I just put a few stitches in a contrast colour inside the back.