SummaryMicrostrip patch antennas (MPA) are widely used in wireless communication systems due to their ease of manufacture, low cost, and low profile. This work proposes a proximity‐coupled rectangular microstrip patch antenna array (PRMPA) adaptable for 5G applications. However, the existing research works suffered from low gain, low efficiency, and narrow bandwidth. In addition, 5G communications suffer from path loss in high‐frequency bands. For managing this issue, the large gain antenna is essential. Hence, this research aims to design and fabricate high‐gain compact 2 × 2 slotted PRMPA for 5G applications. The antenna design is simulated on HFSS and operates at 28–37 GHz. Here, the antenna parameters like length, width, and feed line parameters are optimized using a metaheuristic optimization like the mayfly optimizer (MFO). Further, a circular‐shaped metamaterial split‐ring resonator (SRR) reduces the mutual coupling. Then, Rogers RT5880 is used as substrate material, and the design operates at 34.5 GHz. The gain and radiation efficiency achieved by the proposed antenna design are 15.4 dB and 94.4% for the simulated outcomes.