Abstract: A punch press die holder assembly includes a die holder body with a fixed rim which partially surrounds an upwardly opening die receptacle within the die holder. The receptacle is dimensioned to receive a punch press die, especially of any various circular dies now in commercial use. Cooperating with the fixed rim portion of the die holder is a moveable clamp member that is a portion of the rim that has a centrally directed surface which contacts the die when the die is in place within the receptacle. A manually operable fastener is operatively connected to the moveable clamp member to hold the clamp member in a closed position for restricting the movement of the die and the fastener is movable by hand to an open position for releasing the clamp member and the die from the die holder so that the die can then be removed and replaced from one side by sliding it horizontally out of the die holder.