Yū Serizawa is a Japanese voice actress and singer born on December 3, 1994, in Tokyo. She is affiliated with the talent agency 81 Produce and the record label Avex. Serizawa is also a member of the voice actress idol group i☆Ris, with which she debuted in 2012 after successfully passing a joint audition held by Avex and 81 Produce. Her motivation to become a voice actor came from watching the anime Full Moon wo Sagashite as a child and a DVD of The Melancholy of Haruhi Suzumiya in junior high school.

Serizawa's career as a voice actor began in 2013. One of her earliest major roles was as Ann Fukuhara in Pretty Rhythm: Rainbow Live. That same year, she also voiced Tenma Ichinotani in Mushibugyō and Maxi Akizuki in Dog & Scissors. A defining role in her early career was Mirei Minami in the long-running PriPara series, a character she played from 2014 onwards across multiple seasons and films. In the years that followed, she built an extensive filmography, taking on a wide variety of characters. Some of her notable leading and supporting roles include Aika Tenkūbashi in Shomin Sample, Yōko Shiragami in My Monster Secret, Iroha Igarashi in Real Girl, the titular Ueno in How Clumsy you are, Miss Ueno, and Yumemi Yumemite in Kakegurui.

Serizawa has been particularly active in the isekai and fantasy genres. She voiced Shera L. Greenwood in both seasons of How NOT to Summon a Demon Lord, Hildegard Minas Lestia in In Another World With My Smartphone, Tanta in Banished From The Heroes' Party, Muria in Fantasy Bishōjo Juniku Ojisan to, and Alma Judikhali in The Most Notorious "Talker" Runs the World's Greatest Clan. Her other prominent roles from the 2020s include Kaname Arisugawa in TONIKAWA: Over The Moon For You, Kikka in the BUILD-DIVIDE anime, Ren Kurogane in Shine Post, Tsubasa in 4-Nin wa Sorezore Uso o Tsuku, Rae Taylor in I'm in Love with the Villainess, and Tsukuyo Aoba in TenPuru. She has also taken on roles in popular sequels, such as Mini Yaemori in the third season of Rent-A-Girlfriend and Rin Kanaoya in The Dangers in My Heart. Her voice work extends beyond anime to numerous video games, including Princess Connect! Re:Dive, Granblue Fantasy, Honkai Impact 3rd, and Zenless Zone Zero.

In addition to her voice acting, Serizawa has a successful career as a singer. As a member of i☆Ris, she has performed numerous anime theme songs and, along with the group, received the Singing Award at the 10th Seiyu Awards in 2016. She launched her solo career in 2017, releasing mini-albums and singles, with her songs often serving as anime tie-ins. Her solo work includes the singles Saiaku na Hi Demo Anata ga Suki and Devikyū, and the full-length album YOUr No.1. She has also performed as a solo artist at Animelo Summer Live, Japan's largest anime music event.

For her performances as a voice actor, particularly in roles like Iroha Igarashi in Real Girl and Yumemi Yumemite in Kakegurui, Yū Serizawa was awarded the Best Supporting Actress Award at the 13th Seiyu Awards in 2019.