A portable electronic device may have an inverted dome switch assembly. The switch assembly may have an inverted dome that has a base and a conductive underside. The base may be attached to a button member. Two electrical contacts in the button member may face the conductive underside. Corresponding conductive traces may be connected to the contacts. The dome may bear against a housing member. The button member may be movable with respect to the housing member from an unactuated position to an actuated position. The dome switch may form a footprint based upon the dome base area. The housing member may extend into a portion of the footprint and not into the remaining portion of the footprint allowing that space to be otherwise utilized.