U with ogonek (majuscule: Ų, minuscule: ų) is a letter of the Latin alphabet formed by addition of the ogonek to the letter U. It is used in Lithuanian,
It is used in Interslavic to denote the etymological presence of a big yus, which evolved into different sounds in Polish and Bulgarian compared to the other Slavic languages. The pronunciation ([o] ~ [ʊ]) depends on the accent of the speaker.
The letter also appears in various Indigenous languages of North America, which are: Chipewyan, Dadibi, Dalecarlian, Gwichʼin, Hän, Iñapari, Kaska, Sierra Otomi, Sekani, Tagish, Tlingit, Tutchone, Winnebago, and Ixtlán Zapotec. In most of them, the letter represent the nasalized close back rounded vowel ([ũ]).