The invention relates to a plug element (2, 2′) of a plug connector (1) for a sealed electrical plug-and-socket connection extending through a hole (4) in a wall (5), having a protective housing (9, 9′), which comprises an inner chamber (46), which at least in places forms a mating plug receptacle (45) for a mating plug element (3) complementary to the plug element (2, 2′), having a locking device (11, 11′), which is actuatable from outside the protective housing (9) and may be moved from an unlocked position (T) into a locked position (R), the locking device (11, 11′) extending at least in the locked position (R) into the inner chamber (46) and overlapping the mating plug receptacle (45) at least in places, and having at least one sealing element (18, 18′) resting against the protective housing (9, 9′) at least in a final plugged-together position of the plug connector (1), by means of which sealing element the mating plug receptacle (45) may be sealed relative to the external environment of the plug connector (1). In order to provide a sealed plug connector (1) with the smallest possible dimensions, provision is made according to the invention for at least one sealing element (18, 18′) to be arranged sealingly between the protective housing (9, 9′) and the locking device (11, 11′) at least in the locked position (R).