Anza Ohyama (Japanese: 大山 アンザ, Hepburn: Ōyama Anza; born May 4, 1976), also known as simply Anza (stylized in all caps), is a Japanese singer and theater actress best known as vocalist of the heavy metal band Head Phones President and for playing Sailor Moon in thirteen separate musical productions.

Anza was born in Cape Town, South Africa, to a White South African mother and a Japanese father. When they moved to Nagasaki, Japan in her childhood, Anza was not fluent in the Japanese language and was bullied because of her foreign appearance. She has a younger sister named Chiho who played Sailor Jupiter in Sailor Moon musicals.^{[citation needed]}

Anza began modeling in junior high school and was invited to shoot a commercial in Nagoya. At fifteen, she made her acting debut on NHK's Chūgakusei Nikki. She made her music debut in 1992 as a member of the pop idol group Sakurakko Club and released a number of singles with them. She and Ayako Morino, also of Sakurakko Club fame, were in a spin-off duo called Momo.

With Anza joining the Sailor Moon musicals in 1993, she appeared regularly on the CD releases for the musicals, both in solo and group songs. From her five-year period as Sailor Moon, she can be heard on the "La Soldier" single (released prior to the very first musical), the first five Memorial Album of the Musical releases, as well as three of the eight compilation albums which have been released since the musicals' conception. In 1994, Moon Lips, a group of actresses from the musicals including Anza, provided vocals for the Sailor Moon anime's theme song "Moonlight Densetsu".

Shortly following her graduation from the Sailor Moon musicals in 1998, she released a solo single entitled "Dream" under the Sony Music Entertainment Japan record label. "Dream" was also featured as the ending theme song for the TV show Famitsu Wave. In April 1999, she released "Tobira wo Akete" (under Victor Entertainment), a single which was used as a theme song for the anime Cardcaptor Sakura. In September 1999, Anza provided vocals for "Ai wo Shizumeteru", the ending theme song to the PlayStation game Psychic Force 2. Another of her songs, "Mienai Chizu", was used as an insert song in episode 68 of Cardcaptor Sakura.

In 1999, Anza went in a completely different direction with her music. She formed Head Phones President with brothers Hiro and Mar, who previously helped her on her solo work. They are a heavy metal band, with occasional screamed vocals interspersed with soft melodic singing. Anza is often introduced as being on "vocals and visuals". They have referred to their music as "'negative', due to their emotional lyrics that stem from traumatic experiences, [but] believe their music expresses their struggles in a hopeful manner." A lot of the lyrics come from Anza; the song "Alienblood" represents her own troubles growing up in Japan as mixed race.

In 2003, Toho recorded four of its Les Misérables musicals live, and they released four double-disc albums (available only by special order directly from Toho). Anza appears on the light blue album with Kazutaka Ishii as Jean Valjean.

In 2006, Anza was signed onto the Universal Music Japan and released her debut single with them: "Kanata e". It was used as the second ending theme song for the anime Glass no Kantai.