A clamp-on paper towel holder has a back plate, a first and second holder arm, one or more clamps and a pop-up retainer. The first and second holder arms work together to grasp both ends of a paper towel roll and suspend the roll therebetween. The clamps mount on the back plate at mounting attachment points. Near each attachment point is a clamp extension against which the user can squeeze the clamp handle when desiring to open the clamp and reposition the holder between mounting locations. The clamps can grasp onto poles, rails, table edges, chairs, etc. and firmly suspend the holder therefrom. A user can simply squeeze the clamp's handles to open the clamps, reposition them, and then release the clamp handles to lock the holder in place. The pop-up retainer keeps the towel roll from unraveling in the wind.