In this manuscript, the realization of penta-band notches with the aid of an ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna for diverse wireless applications is demonstrated. A single port UWB antenna is utilized to construct the proposed MIMO antenna, which comprises an altered patch loaded with three U-shape slots and an inverse U-shape slot on the feed line followed by a C-shape stub adjacent to the feed line. These slots and C-shape stub are liable to generate five notches at 3.4 GHz (3.16-3.67 GHz), 4 GHz (3.88-4.10 GHz), 4.6 GHz (4.56-4.75 GHz), 5.7 GHz (5.65-5.92 GHz), and 7.8 GHz (7.39-8.12 GHz), respectively. These notches depreciate interference from WiMAX, C-band, WLAN and X-band (satellite communication) frequencies. Alternatively, the reported antenna can also be utilized as a proximity radar (8-12 GHz) in X-band. The proposed antenna engraved on a Rogers RT/Duroid 5880 substrate having an overall size of 80 × 80 × 1.6 mm3 or 0.8λ0 × 0.8λ0 × 0.016λ0 (λ0 is the free-space wavelength at lowest frequency 3 GHz). Simulation and experimentation have been performed to corroborate the performance of the reported antenna. Results emphasize that the proposed MIMO antenna operates from 3 GHz to 14 GHz with measured peak gain 4.8 dBi, radiation efficiency above 82% and isolation less than -20 dB. Except at notches, the computed envelope correlation coefficient (ECC) is less than 0.03; diversity gain (DG) is approximately 10; total active reflection coefficient (TARC) is less than -10 dB; channel capacity loss (CCL) is less than 0.35 bps/Hz. These characteristics qualify it as a multifunctional antenna for wireless applications, lowering the antenna count needed in compact wireless devices.