The objective of this research was to investigate the photodegradation of dissolved lignin in a water medium resulting from titanium dioxide photocatalysis reactions that were conducted in a batch system. All experiments were carried out using the single factor design method. It was determined that irradiation in the absence of the catalyst allowed for only a 4.6% reduction in the dissolved lignin concentration (0.02 g) after 2 h. However, with a 10 mg/L loading of TiO2, an 82% decrease in the total lignin concentration was obtained. Both titanium dioxide loading and illumination intensity were also studied to determine optimum operating conditions. An optimal titanium dioxide loading of 10 mg/mL was determined, and it was found that higher illumination intensities correlated well with higher initial degradation rates and total lignin degradation.