FIG. 1 is a perspective view of the transparent side-opening waste receptacle of the present design; FIG. 2 is a front view thereof; FIG. 3 is a rear view thereof; FIG. 4 is a first side view thereof; FIG. 5 is a second side view thereof; FIG. 6 is a top view thereof; and, FIG. 7 is a perspective view thereof shown with a side door in an open position.