Kepler-438 is an orange K-type dwarf (about 0.54 solar masses, 3,748 K, 0.52 solar radii). Kepler-438 b is a planet with 1.1 Earth radii, with an orbital period of 35.2 days, at 0.166 AU from its star, discovered in 2015 via transit. At least one planet may receive an Earth-like flux of starlight, placing this system on the short list of potentially habitable worlds worth detailed atmospheric study. Kepler-438 b orbits well inside Earth's distance from the Sun. At 1.1 Earth radii, Kepler-438 b is a compact world comparable in size to rocky planets in our Solar System.