An accessory such as a wireless earbud may have an antenna for transmitting and receiving wireless signals. A housing for the earbud may have a main body portion and an extended portion that forms a stalk protruding from the main body portion. The earbud may have a speaker aligned with a speaker port in the main body portion. The antenna may have an elongated shape and may extend along the stalk. The stalk may have a plastic housing wall portion. The antenna may be formed from first and second metal traces on opposing sides of a printed circuit substrate. The first metal trace may form an antenna resonating element arm and may lie between the substrate and the plastic housing wall portion. The second metal trace may be a ground trace. A feed for the antenna may be located at a juncture between the main body portion and the stalk.