Provided are an antenna apparatus and an electronic device. The antenna apparatus comprises a plurality of antenna units, spaced from each other; a plurality of decoupling networks, corresponding to the plurality of antenna units one to one; and a decoupling transmission line. Each of the decoupling networks comprises a first transmission line and a second transmission line; an end of the first transmission line is configured to be connected to a radio-frequency chip, the other end of the first transmission line is connected to an end of the second transmission line, a decoupling port is formed at a joint between the other end of the first transmission line and the end of the second transmission line, and the other end of the second transmission line is connected to a corresponding antenna unit; and the decoupling transmission lines is connected between adjacent decoupling ports. The electronic device comprises the antenna apparatus.