Ren Ōsugi, born Takashi Ōsugi on September 27, 1951, in Komatsushima, Tokushima Prefecture, Japan, was a prolific Japanese actor whose career spanned from 1973 until his death in 2018 at the age of sixty-six. While he was primarily known as a highly respected live-action film and television actor, he did perform voice work for several anime projects. His extensive career in front of the camera saw him work frequently with notable directors such as Takeshi Kitano and Takashi Miike, and he received the Best Supporting Actor award at the 1999 Yokohama Film Festival for his roles in films like Cure and Hana-bi.

In the realm of anime voice acting, Ōsugi is known for the role of Agashi in the 2006 science fiction film Origin: Spirits of the Past (also known as Silver-Haired Agito). In this production, he voiced the father of the main protagonist, a character who has largely transformed into a tree after overusing his enhanced powers. His other animated voice role includes the character of Saito Toshio in the 2000 supernatural horror film Uzumaki, an adaptation of the Junji Ito manga of the same name.

Ōsugi's career was, however, far more extensively defined by his live-action performances. Among his many notable roles in television and film are the character Shintaro Jinno, a homeless shogi player known as Nikogami, in the 2008 television drama 81diver. He played Tōru Sasayama in the 2000 horror crime television series MPD Psycho, a role in a production directed by Takashi Miike who admired Osugi's ability to shift between comedic and serious tones. In the 2005 film Densha Otoko, he played the role of the drunkard, also described as a middle-aged man on the train, who is the catalyst for the film's plot. He also appeared as Yochi Hamamoto in the 1995 film Weather Woman (A Weather Girl) and as Kiyotsugu Ōkōchi, the Prime Minister, in the 2016 film Shin Godzilla. Ren Ōsugi passed away on February 21, 2018, due to heart failure.