Setsuo Wakui was a Japanese actor and voice actor born on March 5, 1932, in Tokyo. His real name was Hiroshi Wakui. He graduated from the Department of Drama at Nihon University College of Art and was affiliated with the Tokyo Actors' Cooperative. His career spanned from the late 1950s until his death on January 18, 1981, at the age of 48.

Wakui was known for his distinctive voice quality, which made him a frequent choice for roles requiring a unique vocal presence. He often portrayed monsters, overweight characters, and villains, where his specialty was creating a spooky atmosphere using utterances with a vibrato effect. This vocal talent led to extensive work not only in anime but also in live-action tokusatsu superhero series, where he voiced numerous monsters and robot characters.

Among his notable anime voice roles, he played Dekapan in the 1966 version of Osomatsu-kun, a role for which he is particularly well-remembered. He also voiced Chibi in Nagagutsu Sanjushi, Urume in Vicke the Little Viking, Katol in Kaizoku Ōji (Prince of Pirates), and Sancho Panza in Zukkoke Knight - Don De La Mancha. In the superhero genre, he provided the voice for characters such as Hidoh in UFO Senshi Daiapolon II, as well as numerous villainous voices in series like Kikaider, Inazuman, and Himitsu Sentai Gorenger. He was also part of the cast for the classic puppet drama Hyokkori Hyoutan-jima. His filmography also includes a role in the anime Ashita no Joe and dubbing work, such as providing the Japanese voice for Curly of the Three Stooges for television broadcasts.