Chlothar II (or Chlotar, Clothar, Clotaire, Chlotochar, or Hlothar, giving rise to Lothair; 584 – 629), called the Great (le Grand) or the Young (le Jeune), King of Neustria, and, from 613 to 629, King of all the Franks, was not yet born when his father, King Chilperic I died in 584.

His mother, Fredegund, is regent until her death in 597, at which time the thirteen-year-old Chlothar begins to rule for himself.

As king, he continues his mother's feud with Brunhilda, queen of Austrasia, with equal viciousness and bloodshed.