The contamination of aquatic ecosystems by crude oil spills is a pervasive issue in Nigeria's oil-producing regions, where waterways are frequently polluted with hydrocarbons, a primary constituent of crude oil. This study examined the phycoremediation capabilities of Chlorella vulgaris using established protocols. The algae isolated from freshwater samples were confirmed to be C. vulgaris. The results of the screening test revealed the organism's capacity to degrade heavy crude oil, as evidenced by varying levels of turbidity in the mineral salts-oil medium. Over a 47-day period, the pH of the mineral salts-oil medium decreased progressively, transitioning from neutral to acidic levels, ultimately reaching a pH of 4.1. Conversely, the absorbance of the medium increased over the same period, indicating C. vulgaris growth. Notably, the residual oil content in the mineral salts-crude oil medium decreased substantially, with a degradation rate of 80%. This study demonstrates the potential of C. vulgaris in phycoremediation of crude oil spills in Nigeria.