An antenna device and an electronic device including the same are provided. The antenna device includes a housing that includes a first plate, a second plate facing a direction opposite to the first plate, and a side member surrounding a space between the first plate and the second plate, a display viewable through at least a portion of the first plate, an antenna assembly disposed within the housing wherein the antenna assembly includes a first printed circuit board, a second printed circuit board, at least one structure interconnecting the first printed circuit board and the second printed circuit board and including conductive paths, a plurality of conductive patterns, and a wireless communication circuit, a flexible printed circuit board, and a third printed circuit board.