O with macron
|The Cyrillic script|
O with macron (Ō о̄; italics: О̄ о̄) is a letter of the Cyrillic script. In all its forms it looks exactly like the Latin letter O with macron (Ō ō Ō ō).
O with macron is used in the Evenki, Mansi, Nanai, Negidal, Orok, Ulch, Kildin Sami, Selkup, Chechen languages.
O with macron also appears in the Transcarpathian dialect of Carpatho-Rusyn, the only Slavic language to do so. In Carpatho-Rusyn, o with macron is pronounced like /oː/ being shifted towards /u/ at different grades. Although the use of this letter is not mandatory and it usually substituted with the Cyrillic letters O or I.