Yuuichi Nagashima is a Japanese actor and voice actor born on December 15, 1957. He is a graduate of Nishogakusha University's Department of Literature and trained at the Bungakuza theater company's research establishment and the Seinenza Theater Company. He began his career under his birth name, Shigeru Nagashima, before adopting the stage name Yuuichi Nagashima. In August 2006, he changed his stage name to Chō, inspired by a character he played in the long-running children's television program Tanken Boku no Machi. He was affiliated with Production Baobab from 1986 until 2007, when he transferred to the Tokyo Actor's Consumer's Cooperative Society (Haikyō).

Nagashima's career is marked by a wide range of character roles in anime, often bringing distinctive personalities to life. He is perhaps best known for providing the voice of the skeleton musician Brook in the long-running series One Piece, a role he has played since the character's debut in 2008. Another of his prominent and long-running roles is that of the imp-like Jaken in Inuyasha. In the 2001 version of Cyborg 009 The Cyborg Soldier, he voiced the shapeshifting Cyborg 007, also known as Great Britain. He also played Vice Principal Hiroshi Uchiyamada in Great Teacher Onizuka and the eccentric high school principal in Nichijou.

His filmography demonstrates a prolific presence in anime across several decades. Some of his other notable anime roles include President in The Super Milk-chan Show, Alpha Q in Transformers: Energon, Ginnosuke Nohara (the second voice of the character) in Crayon Shin-chan, and the Principal in the Hidamari Sketch series. He has also been involved in numerous other projects, such as providing the voice of Gendai Poyota in Mama wa Poyopoyo-Saurus ga Osuki, the role of Chacha in BuBu ChaCha, Kentarou Kamui in Muteki Ō Tri-Zenon, and Pasah in Kouchuu Ouja Mushiking ~Mori no Tami no Densetsu~, among many others. He also took on the role of Matal Mogamett in Magi: The Kingdom of Magic.

Beyond anime, Nagashima has an extensive career in dubbing foreign films and television series into Japanese. He is well-known for providing the Japanese voice of Gollum in The Lord of the Rings film trilogy. His other dubbing roles include Seymour Simmons in the live-action Transformers films, Blitzwing in Transformers: Animated, Elmer Fudd in various Looney Tunes media, and Neelix in Star Trek: Voyager. He also voiced Tarantulas in the Japanese dub of Beast Wars: Transformers.

Nagashima is also a licensed teacher of calligraphy.