Barium titanate (BaTiO3) single crystal with a tetragonal phase was characterized by nanoindentation. Elastic and elastic–plastic deformation regimes were obtained. The main objective was the evaluation of the anisotropic behavior related to mechanical properties associated with the cross-section of the ferroelectric a- and c-domains (In-plane and out-of-plane) in (001) configuration domains. This behavior was evaluated along a line perpendicular to the between domains, which demonstrated that the mechanical properties of the BaTiO3 single crystal depend on the distance from due to the effect of the influence of the neighbor domain. A three-dimensional (3D) finite element (FE) model was developed to simulate mechanical effects revealed by the nanoindentations test. The FE simulation demonstrated that there is no simple isotropic mechanical behavior associated with the domain type. Numerical simulations and experiments performed to study ferroelastic switching domains in BaTiO3 crystals revealed the interaction of the 90°-ca domain with the indentation position.