The Anfillo are from the Omotic language group and have linguistic similarity with Shakacho. The Anfillo people were originally speakers of the Nilo-Saharan language but, abandoning it, shifted to the Omotic language of their conquerors, the Busasi from Kefa when they fell under their domination in the seventeenth century AD. Because of the severe repression and slavery which they experienced under the Busasi, the Anfillo people fled from their original land to Anfillo which is located at the heartland of Wellega.

Coming into contact with the Oromo people of Wellega, once again they abandoned their Omotic language to become speakers of the Oromo language. Today the Southern Mao of the Anfillo people found around Anfillo in Oromiya Regional State are all native speakers of Oromiffa. The Mao are agriculturalists growing maize, durrha, tef, barley, beans, coffee, and enset. They make much use of honey and press beeswax into cakes which they sell in quantities. Cattle are scarce, but numerous goats and sheep are to be found. They are good hunters who could organize hunting lasting for a week. Their diet consists of milk and butter from sheep and goats.

According to Cerulli, the southern Mao have modeled their social and political organizations on that of their Sidama overlords, the Busasi, based on the Kefa feudal system. They have a hereditary king or chief (kedderaso) who rules through four clan heads (niho) who are elected by the elders. The Kedderaso himself is, in turn, subject to the chief (taro) of the Busasi, the Cushitic ruling class of the province.

In marriage, the custom is clan exogamous. Marriage is concluded by means of an exchange of brides between two clans, the bride, usually given to the other clan being the suitor's sister.

The Mao believe in a supreme being whom they call Yere, who has two assistants. The first, Sanci Gai, is the creator of the Mao to whom prayer is made in the event of an epidemic. The second, Karifo, is the lord of the rain, and prayers are made to him for the success of the harvest.

Scripture Prayers for the Oromo, Anfillo in Ethiopia.