The present disclosure provides a positive electrode active material for a secondary battery, comprising: a lithium nickel-based oxide doped with a doping element (M′), wherein the doping element (M′) is at least one selected from the group consisting of titanium (Ti) and magnesium (Mg), wherein when the doping element (M′) is Ti, the doping content of Ti is 3000 ppm to 5000 ppm based on the total amount of the lithium nickel-based oxide excluding the doping element, wherein when the doping element (M′) is Mg, the doping content of Mg is 500 ppm to 5000 ppm based on the total amount of the lithium nickel-based oxide excluding the doping element, and wherein when the doping element (M′) is Ti and Mg, the total doping content of Ti and Mg is 3500 ppm to 5000 ppm based on the total amount of the lithium nickel oxide excluding the doping elements.