A rapid, high voltage capacitor charging power supply (CCPS) based on a third order resonant converter topology has been proposed, analyzed, and simulated using the PSpice software, and as a proof of concept, a prototype of the 6.0 kV, 6.0 A CCPS is also developed. High charging power, low resonant current, and high pulse repetition rate were targeted in the design. In this paper, ac analysis for the calculation of impedance and resonant frequency, and frequency dependence on current gain, and the steady state analysis of the proposed scheme have been studied and presented. The performance is analyzed by simulating the circuit for two values of load capacitances. The simulation and prototype results show linear charging of the load for both values of load capacitances. The charging times of 1.47 and 0.97 ms have been achieved for load capacitances of 1.5 and 1.0 µF, respectively. The performance of the LLC topology has been compared with a conventionally used series resonant scheme. A high charging power of 18.4 kJ/s has been achieved. The topology shows a faster charging rate by ∼36% in comparison with the series LC resonant topology. The results of the analysis match with the simulation and prototype results, which confirms that the proposed scheme is suitable for rapid and reliable CCPS applications.