Mayu Udono is a Japanese voice actress and singer from Hiroshima Prefecture, born on August 16, 1989. She is affiliated with the talent agency Kaleidoscope. Standing 170 cm tall with blood type O, she originally aspired to become a professional ballerina. This ambition led her to study ballet at prestigious institutions, including the Elmhurst School of Dance in the United Kingdom and the Tanya Pearson Classical Coaching Academy in Australia. However, at the age of 18, a back injury forced her to abandon her dance career. Following this setback, she decided to pursue a new path in the performing arts and enrolled at the Tokyo Animator Academy to study voice acting.

Udono made her debut as a voice actress in 2009. Her early anime roles included small parts in series such as Amagami SS in 2010 and Onee-chan ga Kita in 2014. Her career became closely associated with the Garo franchise, beginning with a role in Garo: The Animation in 2014. She has since appeared in multiple installments of the series, providing voices for various characters. In the 2016 animated film Garo: Divine Flame, she played the role of Garum. In the television series Garo: Crimson Moon, she voiced the character Inari (referred to as Inari (Heaven) in some credits) and also performed theme songs for the show as part of the vocal group San Kokushin Hayashi. She later voiced Stella in Garo: Vanishing Line and returned as Inari for the 2018 film Usuzumizakura -Garo-.

One of her most widely recognized roles is Runa Yomozuki in the popular anime series Kakegurui, a part she played across both seasons of the show. In the 2020 anime adaptation of Dorohedoro, she voiced the small, magical creature Kikurage, as well as the mushroom characters Aitake and Maitake. Other notable roles include Elsa in the short-form anime Nyanko Days.

In addition to her voice work in anime, Udono has also lent her voice to video games, including roles in Moero Crystal and Five Kingdoms. Her versatility as a performer extends to live appearances; she has participated in stage plays and musicals, and has worked as a reporter and personality on television and radio programs.