To provide a piston ring and a piston for an internal combustion engine, which have oil scraping-off performance while surely sealing gas, enable reduction in the weight of the piston, friction, and cost, and enable improved assemblability.

The piston ring 10 according to the invention, comprises: a gas seal annular sliding part 13 slid with a cylinder bore inner wall and sealing the gas; an oil scraping-off annular sliding part 14 slid with the cylinder bore inner wall and scraping off the oil; and a gas seal-oil scraping-off annular sliding part 17 with both gas seal function and oil scraping-off function, disposed between the gas seal annular sliding part 13 and the gas seal annular sliding part 13. The gas seal annular sliding part 13, gas seal-oil scraping-off annular sliding part 17, and oil scraping-off annular sliding part 14 are integrally formed in a vertical direction in a base part 15 disposed in a ring groove 12, and a clearance 16 is formed between either of the annular sliding parts or different annular sliding parts.