TOI-5398 is a Sun-like G-type star (about 1.15 solar masses, 6,000 K, 1.05 solar radii), 131 light-years from Earth. TOI-5398 c is a 11.8-Earth-mass planet, with an orbital period of 4.8 days, at 0.057 AU from its star, and an equilibrium temperature near 1,242 K, on an eccentric orbit (e ≈ 0.14), discovered in 2023 via transit. TOI-5398 b is a 0.18-Jupiter-mass companion, with an orbital period of 10.6 days, at 0.098 AU from its star, and an equilibrium temperature near 947 K, on an eccentric orbit (e ≈ 0.13), discovered in 2022 via transit.