Rina Kawaguchi is a Japanese voice actress and singer from Saitama Prefecture, born on November 24. She is affiliated with the talent agency Aoni Production and has been active in the industry since around 2019.

Her early career included minor roles in series such as Rifle Is Beautiful, One Piece, and Digimon Ghost Game. In 2021, she voiced the Valkyrie Reginleif in the Netflix anime Record of Ragnarok, which marked one of her first named roles in an anime series. She also provided voices for the characters Jaimie and Sky in the 2022 anime series Sylvanian Families: Flare no Happy Diary and its subsequent sequel. The same year, she voiced Quan in Kizuna no Allele, an anime project tied to the virtual YouTuber Kizuna Ai. As part of the in-anime unit PathTLive, which performed the series' theme songs, she contributed to the franchise's musical aspect.

Kawaguchi's role as Luca Ikaruga in The Idolmaster Shiny Colors, a spinoff of the popular The Idolmaster franchise, has been a significant part of her career. She joined the series in 2021, voicing a member of the unit Cometik, and performs character songs for the games and related live events. She has shared that she was a fan of the franchise's mobile game, The Idolmaster Cinderella Girls: Starlight Stage, prior to her involvement with Shiny Colors. In 2023, she was cast as Ai Kamiyo in the supernatural anime Dark Gathering. Her first leading role in a television anime series was announced for 2025, when she was cast as the protagonist Nico Wakatsuki in the comedy anime Witch Watch. Her body of work also extends to video games, with roles in titles such as Monster Strike, Kemono Friends 3, and Reynatis.