Rikako Yamaguchi is a Japanese voice actress born in Tokyo on March 30, 1988. She is affiliated with the talent agency Kenyu Office, having moved there in 2023 after previously being with Sun Music Production. She made her debut as a voice actress in 2006.

Yamaguchi's career encompasses a wide range of roles in anime television series, original video animations, and video games. One of her most prominent and long-running roles is voicing the character Rio Momose in the popular multimedia franchise The Idolmaster Million Live!, a role she has played since 2013 in the games and later reprised in the 2023 television anime. Her other notable anime roles include Monjirō in Akame ga Kill!, Shiina in the Hulaing Babies series, Hijiri Minowa in Bakuon!!, Fraw-san in Mobile Suit Gundam-san, Osaki-ko in Hiiro no Kakera - The Tamayori Princess Saga, as well as Sachi Nogami and Michi Kondō in Lagrange: The Flower of Rin-ne. She also voiced Yamaguchi in Nyuru Nyuru!! Kakusen-kun 2-ki. Beyond these, her filmography includes roles in series such as Red Garden, Devil Survivor 2: The Animation, Ace of Diamond, and many others.

In addition to her voice work, Yamaguchi has contributed to theme songs and character songs for several of her series. For instance, she performed the ending theme for Chitose Get You!! as part of a duo and was a member of the group Nyuruz, which performed the theme song for Nyuru Nyuru!! Kakusen-kun 2nd Season. She has also released a solo single.

Outside of her core voice acting profession, Yamaguchi is known for her unique and well-documented interest in studying and promoting chikuwa (a type of Japanese fishcake). This hobby has become a personal trademark; she refers to herself as Chikuwa P, a title that was officially recognized by the National Association of Fish Paste Product and Fisheries Processors Cooperative. Her career has continued steadily, with recent and upcoming projects including roles in anime such as Cue! and YuruYuri★HappyGoLucky.