It is an object to provide a surface-treated steel sheet which contains no Cr, which is excellent in wet resin adhesion, and which can be used as an alternative to a conventional tin-free steel sheet and to provide a resin-coated steel sheet produced by coating the surface-treated steel sheet with resin. A surface-treated steel sheet including an adhesive layer which is disposed on at least one surface of the steel sheet and which contains Ti and at least one selected from the group consisting of Co, Fe, Ni, V, Cu, Mn, and Zn, the ratio of the total amount of Co, Fe, Ni, V, Cu, Mn, and Zn to the amount of Ti contained therein being 0.01 to ten on a mass basis, and a method for producing the surface-treated steel sheet.