Mariko Miyase is a Japanese voice actor affiliated with the agency Mashup Entertainment. She was born on November 2nd, though her birth year is not publicly documented. Originally from Kōchi Prefecture, she was raised in Neyagawa, Osaka. Before pursuing voice acting, she attended the Osaka Mode Gakuen and trained as a makeup artist. She later enrolled at the Japan Narration Acting Institute to receive her professional voice actor training.

Her career began under the name Mariko Miyaji while she was affiliated with Joint Office. In February 2016, she transitioned to freelance work and adopted the stage name Mariko Miyase. She has been with her current agency, Mashup Entertainment, since July 2020.

Miyase has built a career with a wide variety of roles in television anime. She is known for her versatility, voicing characters ranging from young women and children to older women and even animal characters. Early in her career, she appeared in series such as My Wife is the Student Council President and Demon Lord, Retry!. In 2020, she voiced the character Louise in the short-form anime series Don't Call Us A JUNK GAME!. Subsequent years saw her take on roles in Banished from the Hero's Party, I Decided to Live a Quiet Life in the Countryside as Liia in 2021, and as a female clerk in Aharen-san wa Hakarenai in 2022. In 2024, she was cast as Komachi in the series Isekai Onsen Paradise. Her other anime credits include Battle Athletes Daiundōkai ReSTART!, Peter Grill and the Philosopher's Time, TenPuru, and My One-Hit Kill Sister.

In addition to Japanese animation, her work extends to other areas of voice performance. She provided the voice for Aliante in the Chinese original net animation A Herbivorous Dragon of 5,000 Years Gets Unfairly Villainized. She has also been active as a narrator for projects like the web anime Tora to Mike. Her skills are utilized in video games such as Magia Break and radio programs, and she has provided voices for commercial campaigns, including one for the Ariel brand.