Industrial wastewater discharge remains a major environmental challenge due to elevated nutrient concentrations, organic loads, and toxic contaminants. Conventional wastewater treatment technologies are often energy-intensive and costly. Microalgal cultivation using industrial wastewater offers a sustainable, low-cost alternative by coupling wastewater remediation with renewable biomass production. The present study investigates the optimization of algal biomass production using textile and food-processing industrial wastewater as nutrient sources. The freshwater microalga Chlorella vulgaris was cultivated under controlled laboratory conditions using varying wastewater dilutions (25–100%), light intensities (100–300 μmol m⁻² s⁻¹), and inoculum densities (0.5–1.5 g L⁻¹). Growth kinetics, biomass productivity, and nutrient removal efficiencies were systematically evaluated over a 14-day cultivation period. Maximum biomass yield (2.8 g L⁻¹) was achieved at 50% wastewater dilution, 200 μmol m⁻² s⁻¹ light intensity, and 1.0 g L⁻¹ inoculum density. Nutrient removal efficiencies exceeded 85% for nitrate and phosphate under optimal conditions. The results demonstrate the technical feasibility of integrating algal cultivation with industrial wastewater treatment, supporting a circular bioeconomy approach. This study provides experimentally realistic data and optimization strategies relevant for scale-up and industrial implementation.