Ansuz is the conventional name given to the a-rune of the Elder Futhark, . The name is based on Common Germanic *ansuz "a god, one of the main deities in Germanic paganism".
The Younger Futhark corresponding to the Elder Futhark Ansuz rune is , called óss. It is transliterated as ą. The Anglo-Saxon futhorc split the Elder Futhark a rune into three independent runes due to the development of the vowel system in Anglo-Frisian. These three runes are ōs (transliterated o), æsc "ash" (transliterated æ) and ac "oak" (transliterated a).
The shape of the rune is likely from Neo-Etruscan a, like Latin A ultimately from Phoenician aleph.