KMT-2019-BLG-0578L is a Sun-like G-type star (about 0.28 solar masses, 5,778 K), 7,300 light-years from Earth. KMT-2019-BLG-0578L b is a 1.20-Jupiter-mass companion, at 2.000 AU from its star, discovered in 2025 via microlensing. Microlensing detections occur when a foreground star's gravity briefly magnifies a background source, revealing planets that are otherwise too faint and distant to observe directly. KMT-2019-BLG-0578L b circles in the outer system, comparable to the Jupiter region. At roughly 7,300 light-years, KMT-2019-BLG-0578L lies far beyond the nearest stars yet remains reachable to large survey telescopes.