Ken Hirai is a Japanese R&B and pop singer.

Since his debut, Hirai has worked as a model, actor, composer, lyricist, singer, and spokesperson.

During his career, Hirai has released 32 singles and 11 albums up until October 2010.

According to Oricon, his single Hitomi Wo Tojite (Close Your Eyes) became the best-selling single of 2004 in Japan. While his compilation album Ken Hirai 10th Anniversary Complete Single Collection '95–'05 "Utabaka" became the best-selling album of 2006 in Japan.

Born on January 17, 1972 in Higashiosaka, Osaka prefecture, Ken Hirai grew up in Nabari, Mie Prefecture. Hirai began his music career back in 1993 when he signed with Sony Music following a competitive audition in Yokohama the previous year while he was a university student[citation needed].

His debut single "Precious Junk" and album were recorded the following year in 1994 and released in 1995[citation needed]. The first single, used as the theme to a TV drama, immediately garnered Hirai attention and his second single, "Katahō Zutsu no Earphone" (片方ずつのイヤホン Katahō Zutsu no Iyahon?) was also used for a drama, further capitalizing on his unique sound. Hirai's debut album, Un-balanced, went on sale the same year and was followed by a second, Stare At, in December 1996