Akiko Ōku (大九 明子, Ōku Akiko, born October 8, 1968),^[1] also romanised as Akiko Ohku, is a Japanese film director.

Ōku was born in Yokohama, Kanagawa.^[2] In high school, she joined a rakugo group. While studying Politics and Economics at Meiji University, she was part of a student theatre troupe. After graduating, Ōku briefly had an office job at a subsidiary of the Ministry of Labour. She then entered a comedy acting school for one year and performed as a stand-up comedian, and afterwards, at age 27, she entered Eigabi School, a film school where director Kiyoshi Kurosawa taught, among others.

While still at film school, Ōku won a screenwriting contest with a script that would become her theatrical feature film debut as director, 意外と死なない (Igaito shinanai, literally "don't die unexpectedly"). The film was released in 1999.^[1] It is about an elementary school teacher troubled by pupils, parents, colleagues and a stalker.

Lost After School (original title 放課後ロスト Hōkago rosuto) is an anthology film released in 2014 consisting of three episodes about high school girls.^[2] The film is based on the shōjo manga World Gaze Clips by Ran Igarashi.^[3] Each episode was directed by a different female director, the other directors besides Ōku being Chihiro Amano and Ai Nagura.^[2] Ōku's segment is titled 倍音 (baion, literally "overtones").

Fantastic Girls (original title でーれーガールズ Dērē gāruzu) was released in 2015.^[2] It is adapted from the novel of the same title by Maha Harada. The word dērē in the title is Okayama dialect and means "very". The story is about two high-school friends in 1980 who reunite 30 years later.

勝手にふるえてろ (Katte ni furuetero) is a romantic comedy released in 2017. It won the Audience Award at the 30th Tokyo International Film Festival, and its leading actress Mayu Matsuoka was nominated for a Japan Academy Film Prize.

Further films by Ōku include 美人が婚活してみたら Bijin ga konkatsu shite mitara / Marriage Hunting Beauty (2019, based on the manga by Arako Toaru) and 私をくいとめて Watashi wo kuitomete / Hold Me Back (2020, based on the novel by Risa Wataya).