Coco Hayashi, born on May 15, 2002, in Hamamatsu, Shizuoka Prefecture, is a Japanese actress and voice actress. Her interest in performance was sparked by her mother's love of Disney films, and her aspiration to become a voice actress was cemented after attending a concert of Nana Mizuki during elementary school, with encouragement from her anime-loving father. She was a member of Space Craft Junior as a child and appeared on the television program Oha Suta in 2013.

Hayashi's professional career began in 2017 when she was one of the successful applicants from approximately 2,000 candidates in the avex×81produce Wake Up, Girls! AUDITION. This led to her debut as a voice actress, starring as Ayumi Hayashi in Wake Up, Girls! New Chapter! and forming the voice actress unit Run Girls, Run! with Yuuka Morishima and Nanami Atsugi. In 2018, she landed her first leading role as Mirai Momoyama in the long-running anime series Kiratto Pri☆Chan, a character she played until 2021 and reprised for the 2018 film Kiratto Pri☆Chan: Kirakira Memorial Live. For her early work, she was a recipient of the Best New Actress Award at the 13th Seiyu Awards in 2019.

March 2023 marked a significant transition in her career. Following the disbandment of Run Girls, Run! and her departure from agency 81 Produce, it was announced that she would take over the role of Setsuna Yūki (also known as Nana Nakagawa) in the Love Live! Nijigasaki High School Idol Club franchise from April 1, 2023, succeeding the previous voice actress. She became a freelancer before joining mitt management in June of the same year. Her other notable roles from 2023 onwards include Taki Shina, the drummer for the band MyGO!!!!! in the BanG Dream! project, a role that involves live musical performance, and Haru Miyako in the TONIKAWA: Over The Moon For You ~High School Days~ anime series. Her versatility extends to video games, with roles such as Sora in Blue Archive.

Her work demonstrates recurring involvement in major multimedia music franchises, where voice acting is combined with live singing and performance. Beyond her core roles, her filmography includes parts in series such as The Promised Neverland, MF Ghost, and World Dai Star. Throughout her career, Hayashi has been known by the nickname Hayamaru. Her hobbies include watching musicals and Takarazuka plays, drawing, and playing the drums, a skill she utilizes for her role in BanG Dream!.