A dual-functional compact low-profile Multi Input Multi Output Antenna Array for multi-band 5G applications is introduced in this article. Two diverse 4 × 4 MIMO antenna systems are formed by the proposed eight elements antenna array. The first four-element system, whose antennas are sited at the four corners of the mobile, can work on a single band of (3.44 to 3.88 GHz) for n66, n65, n39, n3, and n2 band applications. The second system cares two wide bands of (4.43 to 5.63 GHz) and (1.68 to 2.30 GHz) for n79, n66, n65, n39, n3, n2, and WLAN bands applications. Theirs antennas are situated in the middle of the mobile printed circuit board. The design foundation for the suggested antenna element is based on a modified Peano-type fractal geometry’s second iteration. The different MIMO antenna systems are recognized by precisely defected system ground. The spatial diversity method and the self-isolation technique are applied on the single band MIMO antenna array to provide isolation of better than (23) dB. In contrast, the isolation of better than 10 and 16 dB in the lower and higher bands, respectively, is obtained based on the self-isolated technique. The antenna gains, antenna efficiencies, antenna S parameters have been considered for antenna performance valuation. With respect to the MIMO performance evaluation, the ECCs are considered. According to the results, these recommended antenna designs are a reliable choice for MIMO requests in 5G mobile phone handsets.