Ōita dialect (大分方言, Ōita-hōgen), commonly called Ōita-ben (大分弁), is a dialect of Japanese spoken in Ōita Prefecture in Kyushu, Japan. Even within the prefecture, regional differences are still prevalent; for example, vocabulary within the Hita and Nakatsu regions tends to differ from that used in other regions of Ōita.

Ōita-ben has been strongly influenced by dialects from the Chūgoku region of Japan. For example, compared to other dialects within Kyushu, the sentence-final particle tai, the contradictory conjunction batten, and the secondary substantive particle to are rarely used. However, the word endings -tcha (emphasizing) and -ken (explanatory) are frequently used.

Apart from the younger generation's tendency to skip the ra when forming some standard Japanese potential verbs ("ra"-removed words), the Ōita-ben usage is considered a fairly old custom. For example: The potential form of miru being pronounced mireru instead of mirareru.

In addition, there are three forms of potential verbs in Ōita-ben, depending on whether the potential is objective, subjective, or related to personal ability.

In general, -yoru refers to the progression or continuation of an action or occurrence, while -choru refers to the completion, continuation, or result of a condition or status. They are common in many western Japanese dialects. -yoru can change to -yon, while -choru can change to -chon as well.

Keiyōshi change form depending on the vowel before the final i. The two vowels combine into one elongated sound.

Oita-ben employs euphonic changes often during rapid speech.

Words in Ōita-ben are accented according to a slight variation of the Tokyo dialect’s pitch accent. The western Hita region, while still considered to utilize the pitch accent of the Tokyo dialect, has some minor differences in intonation, while areas close to the inland Kumamoto and Miyazaki Prefectures sometimes utilize the “no accent” pitch that is characteristic of those prefectures.