Kepler-1780 is a Sun-like G-type star (about 0.87 solar masses, 5,403 K, 0.87 solar radii), 791 light-years from Earth. Kepler-1780 b is a planet with 3.6 Earth radii, with an orbital period of 109 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 791 light-years, Kepler-1780 lies far beyond the nearest stars yet remains reachable to large survey telescopes.