There is growing interest in reclaiming waste materials from industries such asmetallurgical slags, fly ash and agricultural wastes in a resource-limited world. A large amount of steelslag is produced as waste material from steel industries. This study focused on natural organic matter(NOM) removal using steel slag as a low-cost adsorbent/catalyst. The aim of this study was toinvestigate the potential use of steel slag to remove NOM in waters with high specific UV absorbance(SUVA254) value. The effects of steel slag particles size and dosages of slag and hydrogen peroxide onNOM removals were determined. UV absorbing NOM fractions were preferentially removed by thesteel slag. Maximum UV absorbance and dissolved organic carbon (DOC) reduction after adsorptionwere 83% and 54%, respectively. In addition to adsorptive properties, iron oxides on steel slag surfacessignificantly catalyses hydrogen peroxide decomposition. As a result of formation of strong oxidantsafter hydrogen peroxide decomposition, NOM removal increased. The results showed that steel slag canbe used as adsorbent and catalyst for removal of NOM in high SUVA value waters. Besides, steel slagmay be effective for controlling the formation of disinfection by-products (DBPs) in drinking watertreatment due to the removal of NOM fractions with high UV absorbance values.