Electronic devices may be provided that include radio-frequency transceiver circuitry and antennas. An antenna may be formed from an antenna resonating element and an antenna ground. The antenna resonating element may have a shorter portion that resonates at higher communications band frequencies and a longer portion that resonates at lower communications band frequencies. An extended portion of the antenna ground may form an inverted-F antenna resonating element portion of the antenna resonating element. The antenna resonating element may be formed from a peripheral conductive electronic device housing structure that is separated from the antenna ground by an opening. A first antenna feed may be coupled between the peripheral conductive electronic device housing structures and the antenna ground across the opening. A second antenna feed may be coupled to the inverted-F antenna resonating element portion of the antenna resonating element.