The growing EV charging infrastructure introduces significant power quality issues due to harmonics from nonlinear loads like diode rectifiers and switching converters. These harmonics increase current/voltage THD, degrade power factor, voltage regulation, and system efficiency, often violating the IEEE 519 standard. This paper presents a comprehensive design and critical analysis of four passive harmonic filter topologies, namely, single-tuned filter (STF), double-tuned filter (DTF), high-pass filter (HPF), and C-type high-pass filter (CHPF), to mitigate harmonics and improve power quality in grid-tied EV charging stations. A generalized model is developed and simulated in MATLAB/Simulink R2021a for an EV charging load, with all filters evaluated under identical conditions based on current THD (I-THD), voltage THD (V-THD), input power factor (PF), voltage regulation (VR), and efficiency. The results indicate that the STF achieves an I-THD of 8.3%, V-THD of 4.6%, PF of 0.92, VR of 6.2%, and an efficiency of 91.3%. The DTF performs slightly better, with an I-THD of 6.1%, V-THD of 3.9%, PF of 0.95, VR of 5.4%, and efficiency of 93.5%. The HPF further improves these metrics, showing an I-THD of 5.6%, V-THD of 3.5%, PF of 0.96, VR of 5.0%, and efficiency of 94.2%. In comparison, the proposed CHPF outperforms all traditional filters, achieving the lowest I-THD and V-THD values of 3.7% and 2.1%, respectively, the highest PF of 0.987, improved VR of 3.8%, and superior efficiency of 96.2%. The results confirm that CHPF offers superior harmonic mitigation, voltage stability, power factor, and efficiency, thereby ensuring better vehicle-grid compatibility.