Abstract: A hair relaxant applicator apparatus for applying a controlled flow of hair relaxant to a person's hair. The apparatus includes a supply unit and an applicator brush interconnected by tubing. The supply unit has a plastic supply container, a reciprocating piston and rod within a bore thereof, and an electric motor that moves the piston rod using reduction gearing. A footswitch and rheostat control the direction and speed of the motor by interconnection with its power supply. The piston extrudes hair relaxant from the supply container, through the tubing, through a passageway within the brush, and out openings in the head of the brush at the base of bristles. The brush has a handgrip with a thumbrest, a pointed tip for parting hair, and a longitudinal ridge for smoothing the applied relaxant. A cap on the supply container may be removed for filling and cleaning the container, and a replacement cap and plug prevent dripping of the hair relaxant when the tubing is separated from the supply container.