Leo /ˈliːoʊ/ is one of the constellations of the zodiac, between Cancer the crab to the west and Virgo the maiden to the east.

[2][3] Leo is also home to a bright variable star, the red giant R Leonis.

[4] Gliese 436, a faint star in Leo about 33 light-years away from the Sun, is orbited by a transiting Neptune-mass extrasolar planet.

Modern astronomers, including Tycho Brahe in 1602, excised a group of stars that once made up the "tuft" of the lion's tail and used them to form the new constellation Coma Berenices (Berenice's hair), although there was precedent for that designation among the ancient Greeks and Romans.

It is at a distance of 37 million light-years and has a somewhat distorted shape due to gravitational interactions with the other members of the Triplet, which are pulling stars away from M66.

The star formation in this region is thought to be due to the presence of the dusty bar, which sends shock waves through its rotation to an area with a diameter of 2,000 light-years.

[10] The Persians called Leo Ser or Shir; the Turks, Artan; the Syrians, Aryo; the Jews, Arye; the Indians, Simha, all meaning "lion".

Some mythologists believe that in Sumeria, Leo represented the monster Humbaba, who was killed by Gilgamesh.

[12] In Greek mythology, Leo was identified as the Nemean Lion which was killed by Heracles (Hercules to the Romans) during the first of his twelve labours.

[10][1] The Nemean Lion would take women as hostages to its lair in a cave, luring warriors from nearby towns to save the damsel in distress, to their misfortune.

[13] The Lion was impervious to any weaponry; thus, the warriors' clubs, swords, and spears were rendered useless against it.

USS Leonis (AK-128) was a United States Navy Crater class cargo ship.