A negative electrode active material including a negative electrode active material particle. The negative electrode active material particle includes a silicon compound particle including a silicon compound (SiOx: 0.5≤x≤1.6). The silicon compound particle includes crystalline Li2SiO3 in at least part of the silicon compound particle. Among a peak intensity A derived from Li2SiO3, a peak intensity B derived from Si, a peak intensity C derived from Li2Si2O5, and a peak intensity D derived from SiO2 which are obtained from a 29Si-MAS-NMR spectrum of the silicon compound particle, the peak intensity A is the highest intensity, and the peak intensity A and the peak intensity C satisfy a relationship of the following formula 1. 3C