The structure of the title complex, [Mg(H(2)O)(6)](C(10)H(15)O(4)S)(2), consists of regular octa-hedral [Mg(H(2)O)(6)](2+) cations and d-camphor-10-sulfonate anions. A three-dimensional supra-molecular architecture is formed via hydrogen-bond inter-actions [O-H⋯O = 2.723 (2)-2.833 (2) Å] to give alternating layers of [Mg(H(2)O)(6)](2+) cations and d-camphor-10-sulfonate anions. The title compound is isomorphous with the zinc, copper, cadmium and nickel analogues.