Since the discovery of its facile synthesis in 2001, meso-aryl-substituted expanded porphyrins have been developed as a new class of azaannulenes in light of their facile redox interconversions, conformational flexibilities involving flipping of the constitutional pyrroles, rich metal coordination behaviors, unprecedented chemical reactivities, effective platforms to realize versatile electronic states including Mobius aromatic and antiaromatic species, and abilities to stabilize organic radicals. In this Review, the syntheses, structures, and optical, electronic, and magnetic properties of meso-aryl-substituted expanded porphyrins and their metal complexes have been updated with a particular focus on the relationship between `aromaticity and molecular twist (molecular topology)". While the importance of the interplay of these two charatleristics has been long recognized from the theoretical viewpoint, meso-arylsubstituted expanded porphyrins offered solid experimental evidence to provide Mobius aromatic and antiaromatic molecules with distinct diatropic and paratropic ring currents, respectively. This attribute is not shared with beta-alkylated expanded porphyrin counterparts, underlining the importance and uniqueness of meso-aryl-substituted expanded porphyrins.