Yūko Okui is a Japanese voice actress affiliated with the agency DAX Production as of April 2025. She was born on January 5th and is a native of Mie Prefecture in Japan. Her career has included associations with other agencies such as IAM Agency and Aslead Company.

Okui's body of work consists primarily of supporting and minor roles in anime television series and films. One of her credited roles is Hina Higurashi in the 2021 animated film Kiniro Mosaic the Movie: Thank You!!. This film serves as the final episode for the Kiniro Mosaic series.

In addition to this film appearance, Okui has been active in various television series, particularly during the 2020s. Her recent roles include Michelle in the 2024 series A Journey Through Another World: Raising Kids While Adventuring, and Munami in both the 2023 and 2025 seasons of Reborn as a Vending Machine, I Now Wander the Dungeon. She also voiced Ayano Mita in the 2023 series The Dreaming Boy is a Realist.

Earlier in her career, Okui took on minor roles in series such as Tonari no Kyuuketsuki-san (as Mikan) in 2018 and Rain in multiple installments of the Rainy Cocoa series between 2015 and 2019. Her other credits include uncredited or background roles in productions like Mikakunin de Shinkoukei (2014), Joukamachi no Dandelion (2015), and Sansha San`you (2016).