This research describes a low-profile frequency reconfigurable monopole antenna working in the microwave frequency range. The suggested structure is printed on a flame retardant-4 epoxy (FR4-epoxy) substrate with a permittivity of 4.4 and tangent loss of 0.002. Three-pin diode switches are fitted between radiating patches to alter the different operating modes of an antenna. The proposed antenna operates in four modes, covering eight different bands by operating at single bands of 4.43 GHz in Mode 1, and dual bands (i.e., 3.5 and 5.66 GHz, 3.1 and 5.5 GHz) in Mode 2 and 3, and triple bands in Mode 4 (i.e., 2.9, 5.2, and 5.7 GHz). The voltage standing wave ratio (VSWR) of the provided antenna is less than 1.4 for all the working bands. The efficiency of the developed antenna is 73 to 93 percent, and the gain varies from 1.39 to 2.57 dBi, respectively, at matching resonance frequencies. The obtained bandwidths at corresponding frequencies varied from 6.5 to 24.15 percent. The suggested structure is modeled in the Computer Simulation Technology microwave studio (CST MWS), and the simulated findings are experimentally confirmed. Due to its fairly modest size and compatibility with numerous wireless protocols, the suggested antenna may be employed in contemporary portable fifth generation (5G) devices as well as Internet of Things (IoT) enabled systems in smart cities.