In this letter, a wideband printed antenna and its arrays for 5G wireless cellular systems have been proposed. The proposed antenna is like the Yagi‐Uda antenna which fed by an optimized microstrip line. The single antennas have two kinds of bandwidth. In broadband case, it has |S11| < −10 dB with an impedance bandwidth of 47% (24.8‐40 GHz) and a range gain of 6.3‐8.9 dBi. In multiband case, it covers two licensed bandwidths for 5G systems (27‐29 GHz and 36‐40 GHz) and a range gain of 7.2‐7.9 dBi. Furthermore, by optimizing the constructive interference between the patches and the aperture, a relatively high antenna gain even with a wide beamforming across an azimuthal plane with the merits of the average gain equal 10.5 dBi could be obtained. The measurement results showed that the proposed antenna and array antenna have stable radiation patterns, low cross‐polarization, and high gain, exhibiting potential use for the applications of 5G wireless communication systems.