Artificial electromagnetic materials, including metamaterials that control resonances, and meta-crystals that govern Bragg scattering, offer extensive tunability in electromagnetic responses, making them an ideal platform for exploring topological properties in photonics. Metamaterials, composed of finely arranged sub-wavelength artificial structures, and meta-crystals, incorporating symmetry-compatible metallic resonators, represent two promising approaches for such investigations. This session highlights various topological phases, both theoretically predicted and experimentally realized, in metamaterials and meta-crystals. Topics of interest focus on various topological phases and artificial gauge fields in photonic metamaterials and meta-crystals. Intriguing structures such as twisted or high-dimensional photonic metamaterials and meta-crystals, combined with novel non-Hermitian or non-Abelian topological phases are also of significant interest.