Kepler-1823 is a Sun-like F-type star (about 1.07 solar masses, 6,000 K, 1.13 solar radii), 725 light-years from Earth. Kepler-1823 b is a planet with 2.1 Earth radii, with an orbital period of 21.1 days, discovered in 2021 via transit. The planet was found when it crossed the face of its star, producing periodic dips in brightness that reveal its size and orbital period to space-based photometry. At roughly 725 light-years, Kepler-1823 lies far beyond the nearest stars yet remains reachable to large survey telescopes.