Kepler-80 is an orange K-type dwarf (about 0.73 solar masses, 4,540 K, 0.68 solar radii), 369 light-years from Earth. Kepler-80 is a compact resonant chain whose tightly spaced planets reveal their masses through transit timing variations. The system hosts 5 confirmed planets on orbits ranging from 23.7 hours to 14.6 days. With 5 confirmed worlds, Kepler-80 is a densely packed system whose resonances, spacing, and formation history are active research topics. Mutual gravitational tugs between the planets can slowly reshape their orbits, preserving clues to the system's assembly. Kepler-80 f skims its star closer than Mercury orbits the Sun. At 1.2 Earth radii, Kepler-80 f is a compact world comparable in size to rocky planets in our Solar System.