Aiko Ninomiya is a Japanese female voice actress born on May 20 in Kanagawa Prefecture, Japan. She is a graduate of the Japan Narration Acting Institute, a prestigious training school for voice actors. Ninomiya was formerly affiliated with ARISE PROJECT but currently works as a freelance talent. Her height is 162 cm, and she holds a regular automobile license.

Ninomiya's voice acting career began around 2015, with her early work primarily in video games. Her professional journey includes a wide array of roles in both television anime and video games, demonstrating her versatility in portraying characters ranging from energetic students to mystical beings.

In anime, Ninomiya has taken on several notable roles. She is recognized for playing NaO in the 2022 series Extreme Hearts, where she voices a member of the metal band BanShee who is the sub-leader and plays the bass. She also voices Rinon in Tsukimichi -Moonlit Fantasy-, a fantasy series that began airing in 2021. Another significant role is Shinji Kazama in the 2020 series Talentless Nana. Her other anime credits include Juliet Sun in Fairy Tail, a female student in both seasons of Love Live! Sunshine!!, various characters in Record of地平线: Destruction of the Round Table, Noto in Sonny Boy, and a female student in Sasaki and Miyano. She also appeared in the film Yo-kai Watch: Forever Friends.

Ninomiya has an extensive catalog of video game credits. Her roles include Maeri in Final Fantasy XIV, multiple characters in the Lord of Vermilion series, Fanatic in Wind Soul, and Coco in Kaden Shoja. She has also contributed to games such as Gal*Gun Double Peace, AKIBA'S STRIP Festa!, Phantom of the Kill, and Alteil Neo. In the multimedia project Onsen Musume, she voices Kuroe Kirishima.

Beyond animation and games, Ninomiya has expanded her work to drama CDs and audiobooks. She has participated in drama CDs such as Ore-sama Teacher and Dakaichi, and narrated the audiobook for 10 Years Left to Live. She has also performed character songs for various projects, including Love Live! Sunshine!! and Phantom of the Kill, showcasing her singing ability.

Ninomiya is known for her special skills, which include singing, hula hooping, and imitating animal sounds. Her hobbies include drawing illustrations, balloon art, and watching international soccer. Colleagues and fans often describe her as having a cheerful and lively personality, making her a popular presence both in her performances and at events.