The present paper reports on the development of a Novel Patch Antenna Array for 4.9 GHz Public Safety WLAN applications. In today’s era of advanced technology, high speed video surveillance is very crucial from security point of view. Public safety surveillance services below 1 GHz are mainly used in voice surveillance services, whereas 4.9 GHz Public Safety WLAN is used for video surveillance services. Accordingly, in this work, 2×2 element antenna array is designed on FR4 substrate using modified triangular patch antenna element with improved gain to the tune of 6.69 dBi. In this research work, biologically inspired Whale Optimization method is used in combination with polynomial curve-fitting technique for the optimization of three different geometrical dimensions of the patch antenna element. The optimized element is further modified geometrically by corner rounding and cut in feed to improve its performance including gain. The proposed antenna array resonates at 4.9 GHz covering 120 MHz bandwidth with an achievement of -15.87 dB reflection coefficient and high gain. Results of simulation study are validated with measured results. The uniqueness of the proposed design lies in the achievement of a large gain using simple patch antenna array designed on readily available low cost FR4 substrate making very easy fabrication. Such an attempt has been rarely reported in the literature. However, the results of present investigations are quite convincing.