This study investigated fish parasites in relation to limnological variables of the Esa-Odo reservoir since the quality of the aquatic environment might influence parasitic infestation in fish. The purpose of this study was to provide information on the parasite species of the reservoir due to their public health concern and their relationship with selected water quality parameters. The water quality and parasite examinations were analyzed based on standard protocols in the laboratory. The results showed that water quality parameters were not significantly different (p > 0.05) across the zones. Seasonally, mean water temperature, pH, TDS, DO, organic matter, COD and turbidity were significantly different (p < 0.05) across the different zones of the reservoir while electrical conductivity, alkalinity, NO3-, and PO43- were not significantly different (p > 0.05). Clinostomum tilapiae, Clinostomum sp., Euclinostomum heterostomum, Procamallanus leavionchus, and Lytocestus sp. were recovered in all the fish sampled. The overall prevalence of the fish parasites was 9.8% with an intensity of 2.13. The result indicated fish parasites had a strong positive correlation with certain water quality properties and parasite abundance which suggested that water quality could determine parasitic loads in fishes of the Esa-Odo reservoir.