HD 128717 is a Sun-like F-type star (about 1.21 solar masses, 6,210 K, 1.25 solar radii), 73.6 light-years from Earth. HD 128717 b is a 19.8-Jupiter-mass companion, with an orbital period of 9.36 years, at 4.850 AU from its star, on an eccentric orbit (e ≈ 0.85), discovered in 2025 via astrometry. HD 128717 adds another data point to the growing catalogue of planetary systems whose masses, orbits, and host-star properties constrain models of planet formation. The planet's marked eccentricity suggests past scattering events or perturbations from unseen companions.