TOI-4342 is a cool M-dwarf (about 0.59 solar masses, 3,866 K, 0.60 solar radii), 61.5 light-years from Earth. TOI-4342 b is a 7.3-Earth-mass planet, with an orbital period of 5.5 days, at 0.052 AU from its star, and an equilibrium temperature near 639 K, discovered in 2023 via transit. TOI-4342 c is a 4.8-Earth-mass planet, with an orbital period of 10.7 days, at 0.080 AU from its star, and an equilibrium temperature near 514 K, discovered in 2023 via transit. Mutual gravitational tugs between the planets can slowly reshape their orbits, preserving clues to the system's assembly.