This study aimed to assess the water quality of selected bodies in Port Harcourt—Elechi Creek, Tourist Beach, and Marine Base—by calculating their Water Quality Index (WQI). Water samples were collected monthly from February to July 2019, and the physicochemical parameters were analyzed following the standard methods of the American Public Health Association (APHA). Nine parameters, including pH, turbidity, total suspended solids (TSS), chemical oxygen demand (COD), and sulfate (SO4), were used to compute the WQI. The data were subjected to analysis of variance (ANOVA) and Duncan's Multiple Range Test (DMRT) to determine any significant differences across the sampling stations. The findings revealed significant variations in most physicochemical parameters, with only temperature showing no significant difference (p<0.05). Seasonal variations were observed in pH, turbidity, TSS, COD, and SO4. The WQI values ranged from 211.776 at Tourist Beach to 303.644 at Marine Base, with an overall average of 258.262. The dry season had a lower mean WQI value (230.350) compared to the wet season (257.074). According to the quality grading, all water bodies fell into Class D and E, indicating poor to unsuitable water quality for domestic use and human consumption. The study emphasizes the need for remediation efforts and public awareness campaigns to mitigate anthropogenic activities, such as pollution and improper waste disposal, which contribute to water quality deterioration in these areas