Akiko Yoshida (吉田亜紀子, Yoshida Akiko, born July 22, 1976) is a Japanese singer and songwriter, who performs under the stage name Kokia (stylized as KOKIA). Her most well known songs are "Arigatō..." (ありがとう..., Thank You) (which reached number 2 in Hong Kong when it was covered by Sammi Cheng) and "The Power of Smile" (which topped at No. 8 in the singles chart). She is also recognized for her numerous contributions to anime/game soundtracks, the most notable being "Ai no Melody/Chōwa Oto (With Reflection)" for the film Origin: Spirits of the Past, "Follow the Nightingale" for the game Tales of Innocence, and "Tatta Hitotsu no Omoi" for the anime Gunslinger Girl: Il Teatrino.

Kokia often performs in Europe, basing her activities in Paris and releasing music through Wasabi Records, a subsidiary of Kazé.