Provided is a positive electrode active material for non-aqueous electrolyte secondary batteries for making high capacity and high output compatible, non-aqueous electrolyte secondary batteries, having the positive electrode active material adopted thereto, and a production method for a positive electrode active material in which the positive electrode active material can be easily produced in an industrial scale. A positive electrode active material for non-aqueous electrolyte secondary batteries, contains: primary particles of a lithium nickel composite oxide represented by at least General Formula: LizNi1-x-yCoxMyO2 (0.95≤z≤1.03, 0