In the title complex, [CoCl2(C10H8N2)2]·3H2O, the Co(II) ion is situated on a twofold rotation axis and exhibits a slightly distorted octa­hedral geometry and is chelated by four N atoms of the two bidentate 2,2′-bipyridine ligands and two Cl− ions. The crystal packing is stabilized by hydrogen bonding formed between chloride ions and adjacent water mol­ecules. One of the two independent water molecules in the asymmetric unit is disordered over two sets of sites, each on a twofold rotation axis, in a 0.734 (17):0.269 (17) ratio.