Hiroki Yasumoto is a Japanese voice actor and narrator affiliated with the agency Sigma Seven. He was born in Yamaguchi Prefecture on March 16, 1977, and is a graduate of Komazawa University's Faculty of Law. He began his career in 2003 and has since become recognized for his deep, resonant bass voice, which he employs across a wide variety of roles in anime, video games, and narration.

Yasumoto's path to voice acting was influenced by his admiration for the narrator Kiyoshi Kobayashi. While working night shifts at a broadcasting company after university, he heard Kobayashi's work and realized he could make a career with his own distinctive voice. His first role through an audition was as a narrator for a television program. One of his earliest significant anime roles, Yasutora Sado in the long-running series Bleach, came through the recommendation of his mentor, voice actor Kōji Tsujitani. This role helped establish him in the industry.

Throughout his career, Yasumoto has built an extensive filmography, frequently playing large-built, powerful, or macho characters due to his commanding voice. However, he has also taken on a wide range of other roles, from serious authority figures to comedic characters. Some of his most prominent and long-running roles include Germany in the Hetalia franchise, Elfman Strauss in Fairy Tail, Agil in the Sword Art Online series, and King in One Punch Man. He has also voiced characters in critically acclaimed series such as Hozuki in Hozuki's Coolheadedness, Bjorn in Vinland Saga, and Yuri in Megalobox. His work spans a broad spectrum, from main characters to supporting roles in productions like Fire Force, Food Wars!, The Rising of the Shield Hero, and many others. He has also contributed his voice to video game franchises such as Street Fighter as Guile and Danganronpa as Nekomaru Nidai.

Yasumoto is known for his frequent collaborations with a wide circle of fellow voice actors. Data from his career shows he has worked with Junichi Suwabe on the most projects, totaling nearly 100 titles. He also frequently co-stars with Yuichi Nakamura, Tomokazu Sugita, and Takahiro Sakurai, among many others. Off-screen, he is known to be close friends with Nakamura and Sugita, often discussing games with them. In addition to his acting, Yasumoto is a prolific narrator for news, information, and sports programs, a field where his deep voice is highly valued. He has also taken on roles as a host and MC for various events and web programs, including the long-running variety show Seiyuu to Yoasobi.