The study aimed at the energy optimization of the electrooxidation treatment of textile wastewater using a boron-doped diamond anode. Wastewaters originating from the dyeing process (DWW, with chemical oxygen demand (COD) of 0.9 g L−1), and from the washing process (WWW, with COD of 0.5 g L−1) were evaluated. The influence of the applied current density on the electrooxidation performance was investigated, with the current density decreased by steps along the experiments, through several current profiles. For the treatments performed at constant applied current density along the experiments, a decrease in the current efficiency was observed, reflected by an increase in the specific energy consumption (SEC) with treatment time. The decrease in the applied current density during the experiments led to a significant decrease in SEC. For DWW, a reduction in SEC from 66 to 18 W h gCOD−1 was achieved by decreasing the applied current density during the treatment, without affecting the treatment time (24 h) or the COD removal (97%, final COD below 30 mg L−1). Regarding WWW, the reduction in SEC was from 340 to 106 W h gCOD−1, mainly due to the lower electrical conductivity and COD of WWW. Alongside high COD removal, a high mineralization degree of the organic compounds and complete color removal were attained for both wastewaters evaluated, disclosing the electrooxidation potential for textile wastewater treatment and reuse.