Disclosed is a dishwasher including a tub, a door, a sump, a rack, a spray arm, a water guide including a supply flow-path for movement of the wash water from the sump and a supply port formed in the supply flow-path, a supply unit including a support body for receiving the wash water, a connection pipe extending from the support body to the spray arm, and an spray arm coupler, and a connection member including a coupling body coupled to the water guide and the support body, and a through-hole formed in the coupling body. The supply unit includes a rearwardly protruding insertion portion, and the connection member includes protrusions spaced apart from each other to define an insertion space for the protruding insertion portion, so that the supply unit is coupled to the water guide as the protruding insertion portion is inserted into one of the insertion space.