A walking assist device includes a plurality of electrodes disposed on a surface of a leg of a user, a stimulation applier configured to apply, to the electrodes, a voltage for applying electrical stimulation to the muscles, and a control unit configured to control the stimulation applier to apply the voltage to one or more target electrodes selected from among the electrodes. The control unit controls the stimulation applier such that a combination of electrodes selected as the one or more target electrodes is different for each of a plurality of motion phases included in a motion cycle of the leg during the walking motion.