An electronic device may have a housing such as a metal housing. Openings may be formed in the housing to accommodate a button, to form a camera window, to form a microphone port, and to form a camera flash window. An input-output component mounting member may be used to mount input-output components to the housing of the electronic device. The input-output component mounting member may have a recess that mates with a corresponding protrusion on the housing. Screws may attach the input-output component mounting member to the housing. The protrusion and recess in the input-output component mounting member may ensure that the input-output component mounting member is accurately aligned with respect to the housing. Input-output components such as a microphone, button switch, camera, and camera flash may be mounted to the electronic device with the input-output component mounting member.