A casting plunger for a casting unit of a casting machine, includes a casting-plunger shut-off valve integrated into the casting plunger, having a valve seat and a valve body interacting therewith, wherein the shut-off valve, in an open position, enables a flow of a melt material through the casting plunger during a melt suction operation and, in a closed position, blocks said flow during a mold-filling operation. The casting plunger has a plunger sleeve, which is placeable against an inner wall of a casting cylinder of the casting unit and contains the valve seat, and a plunger ram which contains the valve body. The plunger sleeve and the plunger ram are movable axially with respect to one another by a predefinable valve stroke.