OGLE-2017-BLG-1140L is a Sun-like G-type star (about 0.21 solar masses, 5,778 K). OGLE-2017-BLG-1140L b is a 1.59-Jupiter-mass companion, at 1.020 AU from its star, discovered in 2018 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. OGLE-2017-BLG-1140L b orbits at roughly the distance of Mars from the Sun. Microlensing events are fleeting, but they uniquely probe cold, distant planets that other methods rarely detect. The 2018 announcement placed OGLE-2017-BLG-1140L among the thousands of confirmed planetary systems mapped since the first exoplanet detections.