Kepler-331 is an orange K-type dwarf (about 0.65 solar masses, 4,347 K, 0.49 solar radii), 580 light-years from Earth. Kepler-331 b is a planet with 1.8 Earth radii, with an orbital period of 8.5 days, at 0.065 AU from its star, discovered in 2014 via transit. Kepler-331 c is a planet with 1.8 Earth radii, with an orbital period of 17.3 days, at 0.105 AU from its star, discovered in 2014 via transit. Kepler-331 d is a planet with 1.6 Earth radii, with an orbital period of 32.1 days, at 0.159 AU from its star, discovered in 2014 via transit.