Yakan is an Austronesian language primarily spoken in Basilan in the Philippines. It is the native language of the Yakan people, the indigenous as well as the largest ethnic group on the island. It has a total of 110,000 native speakers. Despite being located in the Philippines, it is not closely related to other languages of the country. It is a member of the Sama-Bajaw languages, which in turn are related to the Barito languages spoken in southern Borneo, Madagascar and Mayotte.

Yakan has a simple five-vowel system: [a], [e], [i], [o], [u], with phonemic vowel length: ⟨ā⟩ [aː], ⟨ē⟩ [eː], ⟨ī⟩ [iː], ⟨ō⟩ [oː], ⟨ū⟩ [uː].

The following chart lists the consonant phonemes of Yakan.

The consonant d is usually realized between vowels as a flap [ɾ], although some speakers use the stop [d] in all positions.

All consonants except for /d͡ʒ/, /h/, /j/, /w/ and /ʔ/ can occur as lengthened consonants.

The following spelling conventions are used: ⟨y⟩ /j/, ⟨j⟩ /d͡ʒ/, ⟨ng⟩ /ŋ/, ⟨'⟩ /ʔ/.