TOI-1899 is an orange K-type dwarf (about 0.63 solar masses, 3,926 K, 0.61 solar radii), 128 light-years from Earth. TOI-1899 b is a 0.67-Jupiter-mass companion, with an orbital period of 29.1 days, at 0.152 AU from its star, and an equilibrium temperature near 378 K, discovered in 2020 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. TOI-1899 b orbits well inside Earth's distance from the Sun.