Miina Tominaga is a Japanese actress and voice singer born Yoshiko Tominaga on April 3, 1966, in Nishi-ku, Hiroshima. She began her entertainment career as a child actor at the age of five and joined the theater group Komadori soon after. Her early on-screen work included a regular role in the tokusatsu series Ultraman Leo from 1974 to 1975, where she was credited under her birth name. Tominaga's transition to voice acting began with dubbing work on foreign television series such as Columbo and Little House on the Prairie. She made her debut in anime in 1977 as the voice of Alice in Rascal the Raccoon. She later adopted the stage name "Miina" on the advice of a fortune teller.

Tominaga's career is marked by a wide range of iconic roles across several decades. In the 1980s, she gained prominence for starring roles in magical girl series as Persia Hayami in Magical Fairy Persia and as Yuka Nitta in Touch. She voiced Lin in Fist of the North Star 2 and Tomomi Murashita in the influential original video animation Megazone 23. A defining role from this era is Noa Izumi, the enthusiastic pilot in the Mobile Police Patlabor franchise, a character she played across multiple television series, OVAs, and theatrical films.

Throughout the 1990s and 2000s, Tominaga continued to take on prominent and diverse characters. She played Maam in the 1991 Dragon Quest: Dai no Daibōken, Karin Aoi in DNA², Miki Hosokawa in Hell Teacher Nūbē, and the young swordsman Myōjin Yahiko in Rurouni Kenshin. In 1998, she assumed one of her most high-profile roles, becoming the third voice actor to play Katsuo Isono, the younger brother in the long-running and beloved family anime Sazae-san. She is also a core part of the Soreike! Anpanman universe, providing the voices for multiple characters, including Rollpanna and, from 2018, the villain Dokin-chan.

Her film work includes a small role in Nausicaä of the Valley of the Wind as Lastelle, and more recently, Brief in the 2020 film Crayon Shin-chan: Crash! Graffiti Kingdom and Almost Four Heroes. Her later television roles include Ritsu Sōma in Fruits Basket, Melody in Hunter x Hunter (2011), and Majorina in Smile PreCure!. Beyond anime, Tominaga has an extensive career in dubbing foreign films and television series, providing the Japanese-language voices for characters played by Jodie Foster in Taxi Driver, Alyssa Milano in Commando, and Tatum O'Neal in Paper Moon, as well as animated roles like Gadget Hackwrench in Chip 'n Dale: Rescue Rangers and Babs Bunny in Tiny Toon Adventures. She has also voiced numerous characters in video games, including Ángel in The King of Fighters 2001 and Squirtle in the Pokémon and Super Smash Bros. series.

Tominaga's work is characterized by a recurring collaboration with the long-running Soreike! Anpanman franchise and the Patlabor series. She has also frequently appeared in adaptations of works by Rumiko Takahashi, such as Maison Ikkoku and Rurouni Kenshin. In recognition of her lasting contributions to the industry and her skill in succeeding esteemed colleagues in long-standing roles, she was honored with the Kazue Takahashi Memorial Award at the 12th Seiyu Awards in 2018. She celebrated her 50th anniversary as a voice actor in 2023.