The adsorption process of reactive blue 49 (RB49) dye and reactive red 195 (RR195) dye from an aqueous solutions was explored using a novel adsorbent produced from the sunflower husks encapsulated with copper oxide nanoparticle (CSFH). Primarily, the features of a CSFH, such as surface morphology, functional groups, and structure, were characterized. It was determined that coating the sunflower husks with copper oxide nanoparticles greatly improved the surface and structural properties related to the adsorption capacity. The adsorption process was successful, with a removal efficiency of 97% for RB49 and 98% for RR195 under optimal operating conditions, contact time of 180 min, pH of 7, agitation speed of 150 rpm, initial dye concentration of 10 mg/L, CSFH mass of 0.2 g/100 mL dye solution, and temperature of 25 °C. According to findings of thermodynamic, adsorption process was a spontaneous, chemical, and endothermic with increased variability at the solid-solution interface during the stabilization of the reactive dyes onto the adsorption active sites. The second-order kinetic model fits the experimental results better, indicating that the chemisorption mechanism controls the adsorption of RB49 and RR195. Meanwhile, the Sips isotherm best fitted to RB49 and RR19, indicating that both heterogeneous and homogenous adsorptions occurred. The findings suggest that CSFH has potential use as an efficient and profitable adsorbent for removing reactive dyes from aqueous solutions.