Leo P is a small, star-forming irregular galaxy located in the constellation Leo, discovered through the blind HI Arecibo Legacy Fast ALFA (ALFALFA) survey, as an ultra-compact high-velocity cloud (UCHVC) of hydrogen gas. Its confirmation as a dwarf galaxy in 2013 suggests that other such UCHVCs are possibly undiscovered dwarf galaxies themselves. Leo P is noteworthy for harbouring one of the most metal-poor environments in the local universe. Its metallicity is just 3% that of the Sun's, meaning that its stars contain 30 times less heavy elements than the Sun. This makes Leo P similar to the pristine environments of primordial galaxies.