In this paper, a low-profile fractal antenna with square ring slots is reported. The newly proposed fractal antenna includes circular ring radiating elements with orthogonally placed square shape slots to achieve ultra-wideband operation. The compact antenna (32 × 28 × 1.6 mm 3 ) is designed and fabricated on an FR4 dielectric substrate, and measurements are performed to validate the simulation results. The simulated and measured results demonstrate that the antenna has −10 dB impedance bandwidth of 9.4 GHz from 4.2 to 13.6 GHz in the ultra-wideband frequency. The measured results reveal that the antenna has omnidirectional radiation characteristics with peak gain of 5 dB in the desired band of operation. The proposed antenna has low cross polarization of −28 dB and radiation efficiency about 88% in the operating bandwidth. The large bandwidth, low cross polarization, and stable radiation characteristics confirm that the proposed antenna may be suitable for ultra-wideband applications.