This study aims to propose a novel adsorbent for removal of malic acid from aqueous solutions. In this context, calcium peroxide (CaO2) nanoparticles as novel adsorbent were synthesized, characterized, and assessed the efficiency of in malic acid removal. Followed this, kinetic, thermodynamic, and equilibrium studies were conducted. The average particle diameter and surface area of CaO2 nanoparticles have been found to be 34.77 nm and 13.58 m2.g−1, respectively. The maximum adsorption capacity of CaO2 nanoparticles for malic acid has been determined as 596.86 mg.g−1. The results showed that CaO2 nanoparticles are effective adsorbent in removing malic acid from aqueous solutions.