Rika Morinaga is a Japanese voice actress, stage actress, and singer born on April 25, 1980, in Tokyo. She is currently affiliated with Mausu Promotion, having previously been represented by I'm Enterprise and Exellex. Her career began on the stage in May 2000 as a member of the angura theater company L'Opéra d'Éclipse lunaire, where she also took on choreography work. She made her voice acting debut in 2002 with a role in the series Wandaba Style. That same year, she formed the voice actor unit Mix JUICE alongside Kana Ueda, Chiwa Saito, and Mai Nakahara.

Morinaga is widely recognized for her role as Souseiseki in the Rozen Maiden franchise, a part she has played across multiple series including the original Rozen Maiden, Rozen Maiden: Träumend, Rozen Maiden: Ouvertüre, and the 2013 series Rozen Maiden: Zurückspulen. This character is frequently cited as her signature and representative role. Another of her well-known performances is as Mawari Zenigata in the comedy series Seto no Hanayome, also known as My Bride is a Mermaid, a role she continued in the OVA episodes. In the Strike Witches franchise, she voices the character Fernandia Malvezzi, appearing in Strike Witches 2, the Strike Witches movie, and World Witches Take Off. She is also known for the role of Makoto in the Minami-ke series.

Her filmography includes a wide range of other television anime roles. She played Tayune in Inukami, Kana Ikeda in the Saki franchise, and Azuma in Horizon in the Middle of Nowhere. Other credits include Ren Kannagi in Kaze no Stigma, Claudia in Claymore, Mamiina in Simoun, Nell in Hamatora, Chiharu in Long Riders, and Kokonpurihito in Duel Masters. She has also appeared in long-running series such as Detective Conan.

In addition to her anime work, Morinaga has a substantial presence in video games. She is particularly well-known for her role as Rita Mordio in the popular role-playing game Tales of Vesperia, a part she also played in the animated film Tales of Vesperia: The First Strike. Her other game roles include Ugnia in Summon Night: Twin Age, Frelia in Ar tonelico 2, and Cocoro Fuyukawa in Remember11.

Beyond voice acting, Morinaga is the lead vocalist for the goth rock band functioncode, which she formed in October 2003 and which made its major debut in 2007. She has also worked as a clothing model for catalogs and websites.