The Knoop hardness anisotropy and plastic deformation markings around the DPH indentation were investigated for an Mn‐Zn ferrite single crystal. Knoop hardness values, which depended primarily on the crystallographic direction, were represented on a standard stereographic triangle. The hardness was maximum in thedirection and minimum in theanddirections. The patterns of the plastic deformation markings show that the ferrite deforms plastically at room temperature by {110}and {111}sli