Erii Yamazaki is a Japanese voice actress and singer born on November 20, 1997, in Chiba Prefecture, Japan. She is affiliated with the talent agency Horipro. Her career in the entertainment industry began after she participated in Horipro's 36th New Star Scout Caravan audition in 2011, which led to her being signed by the agency. She made her debut as a voice actress in 2012 and landed her first major role in 2013 as Moe Morita in the television anime series Samurai Flamenco.

In 2014, Yamazaki formed the musical unit every♥ing! with fellow voice actress and singer Kido Ibuki. The duo was active until 2017, when they held their graduation concert. Yamazaki pursued a solo singing career, releasing her first album, "Subete, Kimi no Sei da.," in November 2016 under the ZERO-A and Nippon Columbia labels. She later established her own independent record label, Cherii Records, in July 2019, under which she continues to release music under the name Erii.

Yamazaki has built a diverse portfolio of voice roles across anime, video games, and film. In 2014, she voiced several characters, including Hibari Torikai in Inugami-san to Nekoyama-san, Roboko in World Conquest Zvezda Plot, and Eto-chan in Meshimase Lodoss-tō Senki Sorette Oishii no?. She also provided the voice for Aria in the video game Omega Quintet that same year. Her role as Remy in the 2016 theatrical anime film Popin Q is another notable credit. In 2017, she was cast as both Materia Sisters, Materia White and Materia Black, in the television anime series Frame Arms Girl. She later reprised these dual roles for the 2019 animated film Frame Arms Girl: Kyakkyau Fufu na Wonderland.