Marina Inoue is a Japanese voice actress and singer born on January 20, 1985, in Tokyo, Japan. A graduate of Gakushuin University's Faculty of Law, Department of Political Science, she has been active in the industry since 2004. Her career began after she won the Grand Prix in the Sony Music SD Group Seiyū Audition in 2003, selected from approximately 2,000 applicants, which led directly to her professional debut.

Inoue's debut role was as the titular character Cossette d'Auvergne in the 2004 OVA Le Portrait de Petit Cossette, for which she also performed the theme song. This role was quickly followed by appearances in various television anime. Her first major breakthrough came in 2007 with her portrayal of Yoko Littner in the critically acclaimed mecha series Gurren Lagann. The same year, she also took on the prominent role of Kana Minami in the long-running comedy series Minami-ke and Chiri Kitsu in Sayonara, Zetsubou-Sensei, marking her as a rising talent in the industry. For her work in 2007, she received the Most Excellent Female Voice Actor award from the radio program Hanako to Guusu no Anime Jaran and the ANIKAN Grand Prix Newcomer Award.

Throughout her career, Inoue has demonstrated a wide vocal range, frequently taking on roles that span from spirited heroines to intelligent young men. This versatility is exemplified by two of her most internationally recognized roles from 2013: the gentle and strategic Armin Arlert in the global phenomenon Attack on Titan and the energetic, otherworldly Tohka Yatogami in the romantic comedy series Date A Live. She has continued to voice Armin Arlert across all seasons, films, and OVAs of the Attack on Titan franchise, a role that has garnered her multiple award nominations, including for Anime Trending Awards for Best Voice Acting Performance and Best in Voice Cast. Another defining role in the action genre is Momo Yaoyorozu in the superhero series My Hero Academia, a character she has portrayed since 2016 across multiple seasons and films.

Her filmography is extensive and includes a diverse array of characters in major series. Notable examples include Yozora Mikazuki in Haganai, Kyōko Mogami in Skip Beat!, Laura Bodewig in the Infinite Stratos series, Mai Zen'in in Jujutsu Kaisen, Jericho in The Seven Deadly Sins, Nao Midorikawa/Cure March in Smile PreCure!, Kana Minami in the Minami-ke series, Iku Kasahara in Library War, Maria "Rio" Rollins Tachibana in Rio: Rainbow Gate!, Yumiko Miura in My Teen Romantic Comedy SNAFU, Sakura Mamiya in Rin-ne, and Valt Aoi in the Beyblade Burst series. In addition to her work in television, she has voiced characters in numerous OVAs, films, and video games, including the female protagonist in Persona 3 Portable.

Beyond acting, Inoue has also worked as a singer and narrator. Early in her career, she released several singles under Aniplex, including the debut single "Hōseki". She has contributed character songs for many of her roles and has performed theme songs for series in which she stars. Her clear and expressive voice has made her a sought-after narrator, providing narration for the Attack on Titan series and, since 2021, serving as a Friday narrator for the Nippon TV news program news zero. She has also hosted radio programs such as Good-Track.

Inoue was initially affiliated with Voice & Heart before moving to Sigma Seven in 2008. In January 2022, she transitioned to her current agency, Aoni Production. Her contributions to the industry were recognized internationally when she received the International Voice Actor Award at the Anime Revolution convention in Vancouver in 2014.