KMT-2024-BLG-1870L is a Sun-like G-type star (about 0.67 solar masses, 5,778 K), 5,480 light-years from Earth. KMT-2024-BLG-1870L b is a 1.06-Jupiter-mass companion, at 3.150 AU from its star, discovered in 2026 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-2024-BLG-1870L b circles in the outer system, comparable to the Jupiter region. At roughly 5,480 light-years, KMT-2024-BLG-1870L lies far beyond the nearest stars yet remains reachable to large survey telescopes.