Provided are electronic devices, an antenna structure and a wearable device. The wearable device includes a metal casing including a bottom casing and a side frame surrounding an edge of the bottom casing and integrally connected with the bottom casing, the antenna structure includes a slot in the side frame, and the slot has a first end and a second end opposite to the first end in the first direction. The first direction is the direction surrounding the edge of the bottom casing; the slot is provided with an opening at the first end, and the opening faces the side away from the bottom casing; in the first direction, length from the first end to the grounding end of the slot is ¼ of operating wavelength; and a feeding terminal is arranged between the first end and the grounding end of the slot, and is close to the grounding end.