Non-Hermiticity fundamentally breaks conventional dimensional restrictions on localization and thus allows robust metallic states even in one-dimensional systems. However, the mechanism of Anderson localization in higher-dimensional non-Hermitian systems, especially anisotropic ones, remains largely elusive. Here, we demonstrate that the interplay between the non-Hermitian skin effect and complex disorder in a three-dimensional anisotropic Hatano-Nelson model drives direction-dependent phase transitions, referred to as anisotropic Anderson localization. As disorder increases, the system undergoes four distinct phases, in which the non-Hermitian skin effect emerges along certain spatial directions, while Anderson localization occurs along others. A reentrant localization transition appears near the spectral edge, driven by the imaginary parts of both energy and disorder. The coherent potential approximation analysis confirms the disorder-induced phase boundaries obtained from finite-size conductance calculations and naturally explains the origin of this reentrant behavior. Finally, complex energy-level statistics not only identify the complete localization threshold but also confirm that the system belongs to the symmetry class $\mathrm{A}$, which is associated with broken rotational symmetry.

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• Anderson localization
• Quantum transport
• Skin effect
• Disordered systems
• Non-Hermitian systems