A positive electrode active material for a non-aqueous electrolyte secondary battery of this invention includes: a lithium nickel composite oxide containing lithium, nickel, and at least one metal element other than lithium and nickel; and a layer containing lithium carbonate, aluminum hydroxide, and aluminum oxide, the layer being carried on the surface of the lithium nickel composite oxide. The lithium nickel composite oxide is composed such that the ratio of the nickel to the total of the nickel and the at least one metal element is 30 mol % or more. The layer is composed such that the amount of the lithium carbonate is 0.5 to 5 mol per 100 mol of the lithium nickel composite oxide. The total of aluminum atoms contained in the aluminum hydroxide and the aluminum oxide is 0.5 to 5 mol per 100 mol of the lithium nickel composite oxide.