Mariko Kouda is a Japanese actress, voice actress, singer, and radio personality. She was born on September 5, 1969, in Miyashiro, Saitama Prefecture. After graduating from Kasukabe Kyoei High School, she studied Communications at Tamagawa University in Tokyo, graduating in 1990. She is affiliated with the talent management firm Aoni Production.

Kouda began her career after graduating from the Aoni Juku training school. Her first major anime role came in 1991 as Shuko in the television animation Goldfish Warning!. Her popularity grew significantly with her performance as Okina in Ghost Sweeper Mikami and as the protagonist Miki Koishikawa in the 1994 series Marmalade Boy, establishing her as one of the most recognizable voice actresses of the 1990s.

Over her extensive career, Kouda has voiced a wide variety of characters. One of her most iconic and enduring roles is Nayuki Minase in the Kanon franchise, appearing in both the 2002 and 2006 anime adaptations, as well as the crossover series Kaginado. Another signature role is Shaolin from Mamotte Shugogetten. Her filmography includes a vast range of other characters, such as Kaya in One Piece, Sakura in Pokémon, Misato in Princess Connect! Re:Dive, Luhy Distone in Nyaruko: Crawling with Love!, and Vepar in Welcome to Demon School! Iruma-kun. She has also been part of long-running franchises, voicing Queen Mirage in HappinessCharge PreCure! and Ikuyo Hoshizora in Smile PreCure!. Her work in original video animations is extensive, including roles like Catty Nebulart in Gall Force: Revolution, Yumi Francois in Tekkaman Blade II, Amy in The Super Dimension Fortress Macross II: Lovers, Again, Nima in Tattoon Master, and the title character in Miyuki-chan in Wonderland. In the 2022 anime Pop Team Epic, she voiced Popuko in one segment, demonstrating her continued relevance in contemporary anime.

In addition to anime, Kouda has been a prolific voice in video games, with notable roles including Febronia in the Xenosaga series, Liana in Langrisser, and Gabriel in Granblue Fantasy. She has also lent her voice to foreign dubs, such as Lindsay Weir in the television series Freaks and Geeks.

Parallel to her voice acting career, Kouda is an established J-pop singer who debuted in 1994. She released numerous singles and albums, many of which charted well in Japan, and her music has been used as anime theme songs. She was a member of the J-pop voice acting group Drops. She has also maintained a significant presence as a radio personality, hosting numerous programs over the years, including the long-running Twinbee Paradise and Kouda Mariko no Game Museum.

Throughout her career, Kouda has built recurring collaborations. Director Naoyuki Ito is known to be a frequent collaborator, often casting her in his works, with her role as Nayuki Minase in Kanon being a prime example. She shares a close friendship and professional relationship with fellow voice actress Kikuko Inoue, with whom she has co-starred in multiple productions and appeared on magazine covers. She also formed the musical unit MK-CONNECTION with voice actress Mami Kingetsu in 2012.

Kouda is recognized as a key figure in the first wave of the "voice actress idol" phenomenon in the 1990s, helping to popularize the combination of voice acting and music careers. Her contributions to the industry and her hometown were acknowledged in 2010 when she was appointed as a PR ambassador for her native Miyashiro Town.