A compact Ultra-Wideband (UWB) circular bowtie antenna for Ground Penetrating Radar (GPR) is presented in this paper. The bowtie antenna is composed of two circular arms with parallel slots at the edges to obtain UWB performance while maintaining compact in size (0.31λmax × 0.19λmax × 0.16λmax). Each slot has a resistor loading at the edges to minimize the size of antenna. In addition, a microstrip balun is designed for impedance matching. The performance of the proposed antenna is investigated by simulations and the results show a UWB operating bandwidth ranging from 0.4 to 3.52 GHz, a relative bandwidth of 159%, a maximum gain of 2 dBi, and lower late-time ringing level compare to the basic antenna.