Kepler-1991 is a Sun-like G-type star (about 0.91 solar masses, 5,478 K, 1.05 solar radii), 856 light-years from Earth. Kepler-1991 b is a planet with 1.5 Earth radii, with an orbital period of 13.3 days, at 0.106 AU from its star, and an equilibrium temperature near 760 K, discovered in 2023 via transit. Kepler-1991 c is a planet with 2.6 Earth radii, with an orbital period of 22.8 days, at 0.153 AU from its star, and an equilibrium temperature near 634 K, discovered in 2023 via transit.