Eiji Miyashita is a Japanese voice actor born on September 26, 1978, in Hyogo Prefecture, Japan. As of 2013, he is affiliated with the talent management firm aptepro. He stands 176 cm tall, has type A blood, and his listed skills include the Kansai dialect, as well as experience in karate, judo, and other martial arts.

Miyashita's path to becoming a voice actor began in his third year of high school, inspired by his childhood admiration for fellow voice actor Kōichi Yamadera. Although he enrolled in a university in Nara on his parents' recommendation, he left after one year to pursue his dream. He then attended the Yoyogi Animation Academy in Osaka while working part-time. Following the advice of an instructor, he entered the training school for Ken Production in the Kanto region and began his professional career around the age of 22. He officially started working as a voice actor in 2003. In an interview, Miyashita recalled that his first memorable named role was Takeo Tsurumaru in the 2003 anime series Shadow Star Narutaru.

Throughout his career, Miyashita has built an extensive filmography in anime, video games, and dubbing for foreign films and series. He is known for playing a wide variety of characters. In 2007, he gained attention for taking on three distinctly different roles: Gen Shishio in Kekkaishi, the character Predator in Bakugan Battle Brawlers, and Raphael in the Japanese dub of Teenage Mutant Ninja Turtles.

Several of his roles are in long-running and popular franchises. He voices Sosuke Sugaya in the Assassination Classroom series, appearing in the television anime, the movie Assassination Classroom the Movie: 365 Days' Time, and the spin-off Koro Sensei Quest!. He also plays Kyohei Kashihara in the Arpeggio of Blue Steel - Ars Nova anime and its films. In the Bakugan franchise, he has voiced multiple characters, including Predator, Airzel, and Lythirius across different series. His work in the long-running Fairy Tail anime includes roles such as Hughes, Rocker, and Jiemma. He is also known for voicing Kenji Ito in Horizon in the Middle of Nowhere and its second season. More recently, he voiced Messar Robin Bastar in the second season of To Your Eternity.

Miyashita's voice work also extends significantly to video games. He is the voice of Reyn in Xenoblade Chronicles and provides the voice for the custom male avatar in Xenoblade Chronicles X. He has roles in popular games such as Homura in Toukiden 2, the character Hajun in Kajiri Kamui Kagura, and Bandeiras Hattori in The King of Fighters XIV. He also voices the characters Iwatooshi and Jiroutachi in the hit game and anime Touken Ranbu. In addition, he provides the Japanese voice for the character Rashid in Street Fighter V.

Beyond anime and games, a substantial part of Miyashita's career involves dubbing, or providing Japanese voices for foreign media. He has dubbed numerous Western films and TV shows. Some of his most notable dubbing roles include Raphael in the various Teenage Mutant Ninja Turtles animations, Frankie in the film Meet the Robinsons, and Luther Waffles in the series Zeke and Luther. He has also voiced characters in major Hollywood films, such as in Jurassic World Dominion.

Miyashita has also been involved in music related to his anime roles. He was a member of the unit Trident, along with fellow voice actors Yūki Ono and Shinobu Matsumoto, which performed music for the Arpeggio of Blue Steel franchise. He has also performed character songs for his roles in series like Touken Ranbu.