Provided are a Cr-free surface-treated steel sheet that has excellent humid resin adhesion and corrosion resistance and that exhibits no streak-like surface defects, a method for manufacturing such a surface-treated steel sheet, and a resin-covered steel sheet using such a surface-treated steel sheet. A surface-treated steel sheet includes a steel sheet; a corrosion-resistant coating, on at least one side thereof, that is composed of at least one layer selected from a Ni layer, a Sn layer, an Fe—Ni alloy layer, an Fe—Sn alloy layer, and an Fe—Ni—Sn alloy layer; and an adherent coating, on the corrosion-resistant coating, that contains Zr and at least one species selected from P derived from a phosphoric acid and C derived from a phenolic resin in a total mass ratio to Zr of 0.01 to 10.