Provided is a steel cord for reinforcing a rubber article in which both the rubber penetrability (rust prevention), and the cord strength and shear resistance are highly achieved. Provided is a steel cord for reinforcing a rubber article including: one core strand 11 having a layered-twisted structure formed by twisting a plurality of steel filaments 1; and a plurality of sheath strands 12 having a layered-twisted structure formed by twisting a plurality of steel filaments 2, wherein the sheath strands are twisted around the core strand. An average value Lc of an amount of clearance between outermost layer sheath filaments constituting an outermost layer sheath of the core strand is from 0.073 to 0.130 mm, and the number of the outermost layer sheath filaments is from 7 to 10.