Contact angles of oil droplets on solid surfaces provide useful insight into surfactant cleaning behavior. Contact angles of hexadecane and MAR-TEMP (R) 355, an industrial quench oil, on stainless steel were measured for ionic surfactant solutions as a function of ionic strength. The ionic strength of sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB) solutions was modified by the addition of sodium chloride. Increases in the contact angle with additions of 1.0 mM and 2.5 mM NaCl were observed for the two oils in SDS and for hexadecane in CTAB. For the industrial quench oil, detachment occurred in CTAB concentrations above the critical micelle concentration; as a result, the equilibrium contact angle measurements were not measured. The critical concentration of CTAB decreased with increasing NaCl concentration. Oil-removal studies indicate that increasing ionic strength by as little as 2.5 mM can result in improved cleaning.