Vehicle seat and commercial motor vehicle with at least one vehicle seat

The invention relates to a vehicle seat (1, 2) with a seat part (4), with a backrest (5) and with a height-adjustable armrest (8), in which the height-adjustable armrest (8) comprises an arm support part (9) and a lever mechanism (10) for raising or lowering the arm support part (9) with a fixed base component part (14), with one or two pivot lever parts (17, 18) articulated to the base component part (14) and with a height-adjustable sub-component part (16) articulated to the one or two pivot lever parts (17, 18) for supporting the arm support part (9), wherein the height-adjustable armrest is characterized by a locking device (30) for locking the lever mechanism (10) with a first locking part (32) arranged on the base component part side and having a first locking toothing (35), with a second locking part (33) arranged on the sub-component part side and having a further locking toothing (36), and with locking means (38) which are arranged to be displaceable relative to the two locking parts (32, 33) by means of an actuating element (46) in such a way that counter-locking toothings (44, 45) of the locking means (38) can be engaged into or disengaged from the locking toothings (35, 36) of the locking parts (32, 33) in order to lock or unlock the lever mechanism (10).