The search for new molecular materials with interesting magnetic properties, using the pseudohalide azide ion and di-2-pyridylamine (dpa, C10H9N3) as a chelating ligand, led to the synthesis and structure determination of the title compound, [Co(N3)2(dpa)2]2SO4·2H2O. The crystal structure comprises discrete [Co(dpa)2(N3)2]+ cations, sulfate anions, as well as H2O solvent molecules. The CoIII cations display a slightly distorted octahedral coordination sphere defined by two N atoms from azide anions and four N atoms from the pyridyl rings of two dpa ligands. In the crystal, extensive C—H...O, N—H...O, and O—H...O interactions result in supramolecular sheets that lie parallel to the ab plane. The sheets are further linked through O—H...N interactions between the water molecules of one sheet and azide anions of another sheet, forming a supramolecular framework.