Fly ash samples collected from the Durgapur Thermal Power Station (DTPS) (Durgapur, West Bengal, India) were designated in regard to their respective collection points, that is, the discharge point (DP), the midpoint between the discharge point and the end point (MP), and the end point (EP) of the ash pond. F1 and F3 represent samples collected from field 1 and field 3 of the electrostatic precipitator (ESP), respectively. The fly ash samples were characterized physicochemically. The removal of some common textile dyes using the fly ash samples has been investigated spectrophotometrically as a function of fly ash dosage, dye concentration, and contact time at ambient conditions. The results of this investigation revealed that the sample F3 was the best among the fly ash samples collected from DTPS. Adsorption studies using a visible light irradiated system have been performed, and the spectral analysis of the photolyzed solution revealed that decoloration of the concerned dyes was greater compared to that observed in the dark under identical experimental conditions.