Yū Aoi, born Yu Natsui on August 17, 1985, in Fukuoka Prefecture, is a Japanese actress and voice actress who began her career in entertainment at a young age. In 1999, she made her stage debut as Polly in a production of the musical Annie. Her film debut followed in 2001 with a role in Shunji Iwai’s All About Lily Chou-Chou, which marked the beginning of a successful career primarily in live-action cinema and television.

Her entry into voice acting came in 2006 when she took on the role of Shiro in the animated film Tekkonkinkreet. This performance marked her first major anime voice role and established her presence in the field of voice over work. She has since voiced characters in a range of notable animated films. These include Kanako Azumi in Children of the Sea, a woman in Penguin Highway, Tetsuko "Alice" Arisugawa in The Case of Hana and Alice, Mīme in Harlock: Space Pirate, Miyori in Miyori in the Sacred Forest, and Sonoshee McLaren in Redline. Her voice roles also include the imaginary companion Ikechan in the live-action film Ikechan and Me.

While voice acting is a component of her career, Yū Aoi is more widely recognized for her extensive work in live-action film and television. Her voice acting roles are often in high-profile animated features rather than recurring roles in television anime series.

Throughout her career, she has received numerous awards for her acting. These accolades include the Japan Academy Prize for Best Supporting Actress, which she won in 2007 for her performance in the film Hula Girls, as well as a Best Actress award from the Japanese Professional Movie Award for her role in Hana and Alice.