The inhabitants of Harar represent several different Afro-Asiatic-speaking ethnic groups, both Muslim and Christian, including Oromo, Somali, Amhara, Gurage, Tigray, and others. Nevertheless, within the walled city, the indigenous Harari are predominant.

The Harari, who refer to themselves as Gey 'Usu ("People of the City") are a Semitic-speaking people once thought to be descended from an Aksumite military outpost. Today, they are most commonly classed as a social and cultural unit rather than as a distinct ethnic group since most families have intermingled with the neighboring peoples, and were welcoming of foreigners into their community.

The language, Harari, constitutes a Semitic pocket in a predominantly Cushitic-speaking region. Originally written in the Arabic script, the Harari language has recently converted to the Ge'ez alphabet.