Kepler-257 is an orange K-type dwarf (about 0.92 solar masses, 5,180 K, 1.04 solar radii), 780 light-years from Earth. Kepler-257 b is a planet with 2.6 Earth radii, with an orbital period of 2.4 days, at 0.034 AU from its star, discovered in 2014 via transit. Kepler-257 c is a planet with 5.4 Earth radii, with an orbital period of 6.6 days, at 0.066 AU from its star, discovered in 2014 via transit. Kepler-257 d is a planet with 5.0 Earth radii, with an orbital period of 24.7 days, at 0.160 AU from its star, discovered in 2014 via transit.