K2-149 is a cool M-dwarf (about 0.59 solar masses, 3,745 K, 0.57 solar radii), 124 light-years from Earth. K2-149 b is a planet with 1.6 Earth radii, with an orbital period of 11.3 days, at 0.083 AU from its star, discovered in 2018 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. K2-149 b orbits well inside Earth's distance from the Sun. At 1.6 Earth radii, K2-149 b is a compact world comparable in size to rocky planets in our Solar System.