Given the adverse health effects of antimony (Sb), there is an increased focus on developing methods to remove this toxic metal from contaminated water bodies. To effectively remove Sb(V), a new nanostructured Fe–Cu–Al trimetal oxide was fabricated using co-precipitation method at ambient temperature. The Fe–Cu–Al trimetal oxide was very effective at removing Sb(V) from water; it had a maximal adsorption capacity of 169.1 mg/g at pH 7.0, a capacity that was competitive with most other reported adsorbents. The obtained amorphous oxide had a high pH point of zero charge (pHpzc = 8.8) and good adsorption Sb(V) efficiency over a wide pH range (4.0–8.0). Sb(V) uptake was achieved mainly through an ion-exchange reaction between Sb(V) ions and hydroxyl groups on the surface of the oxide. Given its good removal performance, high selectivity, and simple synthesis, this novel Fe–Cu–Al trimetal oxide offers a promising alternate for removing antimony contamination from aquatic environments.