TOI-3856 is a Sun-like G-type star (about 1.10 solar masses, 5,622 K, 1.05 solar radii), 314 light-years from Earth. TOI-3856 b is a 0.54-Jupiter-mass companion, with an orbital period of 2.0 days, at 0.033 AU from its star, and an equilibrium temperature near 1,544 K, on an eccentric orbit (e ≈ 0.08), discovered in 2025 via transit. The inner world is a hot Jupiter — a gas giant hugging its star at a fraction of Mercury's distance — a class that forced astronomers to rethink how giant planets form and migrate inward.