Mia Sinclair Jenness is an American actress recognized for her voice work in English-language adaptations of anime films and series. Her career began on Broadway and in theater, with early credits including the national tours of Matilda the Musical and Les Misérables, before expanding into television and voice acting.

In anime voice acting, Jenness is known for providing the English voice for the lead character Kanna Hayama in the 2021 fantasy film Child of Kamiari Month. The film follows a young girl on a supernatural journey to deliver offerings to the gods, and Jenness's performance was noted for conveying the character's grief and determination. She also voiced the character Umi in the English dub of the 2011 anime film A Letter to Momo.

Jenness gained wider recognition for her role as the voice of a young Powder in the first season of the critically acclaimed Netflix animated series Arcane, which is based on the League of Legends video game franchise. Her performance in the Emmy Award-winning series contributed to her profile as a prominent young voice in animation.