AT2021ueyL is a cool M-dwarf (about 0.49 solar masses, 3,680 K), 1,040 light-years from Earth. AT2021ueyL b is a 1.34-Jupiter-mass companion, with an orbital period of 11.4 years, at 4.010 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. AT2021ueyL b circles in the outer system, comparable to the Jupiter region. At roughly 1,040 light-years, AT2021ueyL lies far beyond the nearest stars yet remains reachable to large survey telescopes.