The effect of adsorbed S at different coverages on the adhesion of Fe(110) surfaces in match and mismatch is examined using density functional theory (DFT). S is adsorbed in atop, bridge, and 4-fold hollow sites on one side of the interface in c(2 x 2) and p(1 x 1) arrangements, corresponding to coverages of 1/2 and 1 monolayer, respectively. The calculated adhesion energy values at different interfacial separations are fitted to the universal binding energy relation [Rose et al. Phys. Rev. B 1983, 28, 1835], and the effect of the S coverages on the adhesive strength is analyzed. The effect of relaxation of the interfaces at equilibrium is also investigated, and the resulting interfacial structures and related magnetic and charge density properties are compared.