Miyu Matsuki was a Japanese voice actor born on September 14, 1977, in Hiroshima Prefecture. A graduate of Keio University, her interest in voice acting was sparked in childhood by the anime series Yoroiden Samurai Troopers. Although her parents initially opposed her pursuing this career path, they permitted her to move to Tokyo for university, where she also studied at the Japan Narration Acting Institute. She made her professional debut in 1998 using her birth name, Mieko Matsuki, in the PlayStation game Otogari: Koishitai! Hito wa Megumarete Dekiteiru. She later adopted the stage name Miyu Matsuki, reportedly for better luck with the kanji characters.

Her career saw significant growth in the early 2000s. In 2000, she was selected in the KSS "My Girl 2000" audition and joined the group "Up Up." Her first regular role in a television anime was in 2002's Nanaka 6/17. The same year, she moved her agency affiliation to 81 Produce and began her long-running participation in the radio program "Cherry Bell" with fellow voice actors Takahiro Sakurai and Kenichi Suzumura. The year 2004 was particularly productive, marking her first lead role in the anime Chou Henshin Cos∞Prayer. She also formed the voice actor unit "SD☆Children" with Tomoko Kaneda.

Matsuki became known for a wide range of roles, often portraying characters with distinct personalities. Some of her most notable performances included Saginomiya Isumi in Hayate the Combat Butler, Fujiyoshi Harumi in Sayonara, Zetsubou-Sensei, and the teacher Yoshinoya-sensei in Hidamari Sketch. She also voiced Kukulkan, also known as Kuko, in the popular series Nyaruko: Crawling with Love. Her filmography includes a diverse array of other series such as the role of Saki Morimiya in the 2014 adult OVA Teacher's Carnal Courses, as well as parts in Dog Days, Fate/kaleid liner Prisma☆Illya, and Shimoneta: A Boring World Where the Concept of Dirty Jokes Doesn't Exist.

Beyond her regular roles, Matsuki was recognized for her collaborative work. In 2013, she was a recipient of the Singing Award at the 7th Seiyu Awards as part of the group "From the New World" (Kochira kara Haigori-tai G) alongside fellow voice actors Asumi Kana and Yuka Otsubo. Throughout her career, she was also an active participant in various radio programs and music projects.

In July 2015, Matsuki took a hiatus from her career to focus on treatment for an illness. She passed away on October 27, 2015, at the age of 38. In December 2015, her agency, with the consent of her family, publicly disclosed that the cause of her death was malignant lymphoma resulting from chronic active Epstein-Barr virus (EBV) infection, a rare disease, to help raise awareness of the condition.