An electronic device includes: a first housing and second housing connected via a hinge, all of which are overlaid by a flexible display; a hinge housing in which the hinge is seated, and a supplementary structure coupled to an edge of the hinge housing to hide at least part of a peripheral edge of the flexible display, wherein the supplementary structure includes a fixing bracket coupled to the hinge housing, a first wing part coupled to the fixing bracket and disposed between the first member and the first housing, a second wing part coupled to the fixing bracket and disposed between the second member and the second housing, and a coupling part coupling the first wing part and the second wing part to the fixing bracket.