A positive electrode active material for non-aqueous electrolyte secondary batteries, including a lithium composite oxide having a layered structure and represented by a formula LiaNiαAlβCoγMδSrxO2-w wherein 0.95<a<1.05, 0.85≤α≤0.95, 0<β≤0.08, 0≤γ≤0.1, 0≤δ≤0.15, 0<x≤0.015, 0≤w<0.05, α+β+γ+δ=1, and M is at least one element selected from the group consisting of Mn, Fe, Ti, Si, Nb, Zr, Mo, and Zn,
- wherein the layered structure includes a Li layer including metal elements other than Li, and a proportion of the metal elements other than Li present in the Li layer is in a range of 1 mol % or more and 2.5 mol % or less based on a total molar amount of the metal elements excluding Li in the lithium composite oxide.