Atsushi Tamaru is a Japanese voice actor born in Hokkaido on February 27, 1986, though he was raised in Saitama Prefecture. He is affiliated with the talent agency Mausu Promotion. His journey to becoming a voice actor began during his high school years when he heard an anime song on a radio program while studying for university entrance exams, sparking his interest in the profession. He later attended a voice actor training school after seeing an advertisement in a magazine during his second year of college. Tamaru is a graduate of the Shibaura Institute of Technology, where he studied electronic information engineering.

Tamaru made his debut in television animation in 2009, voicing the character Sasaki-san in the series Kupū~!! Mamegoma!. He was initially affiliated with Sigma Seven, having passed their second public audition in 2007 alongside fellow voice actors Asuka Ōgame, Asuka Nishi, and Mai Fuchigami. In April 2020, he announced his transfer to his current agency, Mausu Promotion. Throughout his career, he has also been active in radio, co-hosting the program BELOVED MEMORIES with voice actor Yuma Uchida starting in April 2015.

Tamaru has built an extensive filmography with a wide variety of roles. He is known for his work as Mikihiko Yoshida in the The Irregular at Magic High School franchise, a role he has reprised across multiple series including The Irregular at Magic High School, The Irregular at Magic High School: Visitor Arc, and the film The irregular at magic high school The Movie: The Girl Who Summons the Stars. Other significant roles include Mochizō Ōji in Tamako Market, Ayato Amagiri in The Asterisk War, and Oliver Horn in Reign of the Seven Spellblades.

His voice acting portfolio includes a diverse range of characters across many genres. He has taken on roles such as Ethelbald in The Faraway Paladin, Shot in The Vampire Dies in No Time, and Thomas Grey, Marquess of Dorset in Requiem of the Rose King. In the fantasy genre, he voices Yashma in Utawarerumono: Mask of Truth and Charles Arbor in Seirei Gensouki - Spirit Chronicles. He has also contributed to sports and school-life anime with roles like Shintaro Enoki in Hinomaru Sumo and Tsumugi Tsukiota in A3! Season Autumn & Winter. His work in the BUILD-DIVIDE franchise includes Naomitsu Enjō in both -#000000- CODE BLACK and -#FFFFFF- CODE WHITE. Other notable credits include Akio Tobikura in I★CHU: Halfway Through The Idol, Kyūji Takahashi in Shirobako, and Koichi "KO-1" Nanase in Gundam Build Divers. He has also appeared in the Jewelpet franchise, including as Granite in Jewelpet Kira☆Deco—!. His voice work extends to Chinese-Japanese co-productions such as Hitori No Shita The Outcast, where he plays Chou Soran. He also lends his voice to characters in magical girl and idol-themed series, such as Hughie in Waccha PriMagi! and its film appearance in King of Prism -Your Endless Call- Miinna Kirameki! Prism☆Tours. More recent roles include Wolfred Scalfarotto in Dahlia in Bloom: Crafting a Fresh Start With Magical Tools, Mikoto Saimyōji in Dead Mount Death Play, Valentine in Sugar Apple Fairy Tale, and Arthur in Mahō Tsukai no Yakusoku - Promise of Wizard. In addition to his work in television and film, Tamaru has a substantial presence in video games, with credits including Azul Ashengrotto in Disney: Twisted-Wonderland, Ichigo Hitofuri in Touken Ranbu, and Ryuki in AI: The Somnium Files – nirvanA Initiative.