A foldable electronic device is provided. The foldable electronic device includes a first housing, a second housing, and a hinge assembly rotatably connecting the first housing and the second housing, the hinge assembly including a first rotator including a first gear configured to rotate about a first axis, connecting to the first housing, a second rotator body, including a second gear configured to rotate about a second axis parallel to the first axis, connecting to the second housing, a first rack gear engaged with the first gear, a second rack gear engaged with the second gear, an elastic member, disposed between the first rack gear and the second rack gear, configured to press the first rack gear and the second rack gear in a direction toward the first gear and the second gear, respectively, and a guide guiding movement of the first rack gear and the second rack gear in accordance with a rotation of the first gear and the second gear.