Reo Tatsumori is a male Japanese voice actor affiliated with the talent agency ACROSS ENTERTAINMENT. He was born on September 23 in Osaka Prefecture, Japan, and stands 186cm tall. Prior to his current affiliation, he was a member of Stardust Promotion and performed under the name Reo Nakanishi (also romanized as Reo Nishinaka). He changed his stage name to Reo Tatsumori when he moved to his current agency on July 1, 2022.

Tatsumori's career as a voice actor began in 2014. His first credited role was the track and field coach in the television anime series Glasslip. That same year, he voiced the role of Hisahiko Wakura in the popular sports franchise Haikyu!!. In the following years, he took on a variety of supporting guest roles in numerous anime series. These included a television host in Seiren, a character named Gori in Million Doll, and Dilan in Case File No. 221: Kabukicho.

His filmography expanded significantly in the early 2020s. In 2020, he voiced the character Superduperking in the webtoon adaptation Tower of God and Lord Rumero in Welcome to Demon School! Iruma-kun. The year 2021 saw him play Kururu in I've Been Killing Slimes for 300 Years and Maxed Out My Level. Other notable anime roles include the Minister in Handyman Saitou in Another World, a Death God in the Bleach: Thousand-Year Blood War arc, and Raji Blois in the series To Become a Real Boy in a Fantasy World.

In 2026, Tatsumori took on the role of Hals in the anime series I Want to Live a Long Life to Dote on My Favorite Stepbrother. He also voices the character Harus in the same production. Beyond television animation, his work includes roles in web anime such as The Island of Giant Insects and Sky-High, as well as in video games. His game credits include Resident Evil Village, Metal Gear Survive, and the mobile game The Seven Deadly Sins: Grand Cross.