Ōi ( Japanese 大 飯 郡 , -gun ) is a district in Fukui Prefecture in Japan .
It has an area of 140.26 km², a population density of 133.18 people per km² and a total of around 18,680 inhabitants. (Status: 2003)
Independent cities ( shi ): Awara | Echizen | Fukui (administrative headquarters) | Katsuyama | Obama | Ōno | Sabae | Sakai | Tsuruga
Imadate-gun : Ikeda | Mikata-gun : Mihama | Mikata-Kaminaka-gun : Wakasa | Nanjō-gun : Minami-Echizen | Nyū-gun : Echizen | Ōi-gun : Ōi | Takahama | Yoshida-gun : Eiheiji