Utada Hikaru (宇多田 ヒカル, born January 19, 1983), who also goes by the mononym Utada (English: /ˈuː tɑː dɑː/), is a Japanese-American singer-songwriter. She debuted under the stage name "Cubic U" in 1998, releasing the English-language album Precious, but rose to prominence in 1999 with the release of her second album (and first Japanese-language release), First Love, which sold over eight million copies in Japan and became the best selling Japanese-language album of all time.

She formerly held the record for the highest first-week sales of an album in a single territory, as her Distance album sold over 3 million copies in Japan during the week of March 28, 2001. She has also had three of her Japanese studio albums in the list of Top 10 best-selling albums ever in Japan (number 1, 4, 8) and six of her albums (including one English-language and one compilation) charting within the 275 Best-Selling Japanese albums list. Utada has had twelve number-one singles on the Oricon Singles chart, with two notable record achievements for a female solo or group artist: five million-sellers and four in the Top 100 All-Time Best-selling Singles. It is estimated that Utada has sold more than 52 million records worldwide, making her one of the best-selling music artists in Japan.

In 2009, she was considered "the most influential artist of the decade" in the Japanese landscape by The Japan Times. Additionally, Utada is best known in the West for making two theme song contributions to Square Enix and Disney's collaborative video game series Kingdom Hearts: "Simple and Clean" (which is the re-written English-language version of her 10th Japanese single "Hikari") for Kingdom Hearts and "Sanctuary" for Kingdom Hearts II ("Passion" in the Japanese version of the song).