Ò, ò (o-grave) is a letter in Catalan, Emilian-Romagnol, Lombard, Occitan, Kashubian, Scottish Gaelic, Taos, Vietnamese, Haitian Creole, and Welsh. It also appears in Italian as a variant of o.
otherwise be pronounced with a long [oː] sound: còd [kɔd] "cod" versus cod [koːd] "code".
Italian
In Italian, the grave accent is used over any vowel to indicate word-final stress: Niccolò (equivalent of Nicholas and the forename of Machiavelli). It can also be used on nonfinal vowels to indicate that the stress falls there or whether an o or an e is open or closed: còrso, "Corsican", vs. córso, "course"/"run", past participle of "correre"). Ò always represents the open-mid back rounded vowel.
Emilian-Romagnol
In Emilian, ò is used to represent [ɔː], e.g. òs [ɔːs] "bone". In Romagnol it is used to represent [ɔ], e.g. piò [pjɔ] "more".
References
Ò Wikipedia(Text) CC BY-SA