Izou Oikawa is a Japanese actor and voice actor born on March 5, 1960, in Yamaguchi Prefecture, Japan. His real name is Tetsuji Sugou, and he is also known by the stage name Izou Oikawa. He is a graduate of the Toho Gakuen College of Drama and Music and is affiliated with the Seinenza Theater Company. He stands 178 cm tall and has B-type blood.

Oikawa's career began in the 1980s, with his first film appearance in the 1987 movie Hachiko Monogatari. While he has maintained a steady career in live-action television and film, appearing in series such as Massan and the long-running franchise Aibou, he is also widely recognized for his voice acting work in anime. His voice acting career has been active since at least 1999, when he began voicing the character Iceburg in the long-running series One Piece, a role he has reprised in various films and video games over the years.

In anime, Oikawa is known for playing a variety of supporting and character roles. In 2022, he voiced Kazuteru Irino in the television series Deaimon: Recipe for Happiness. In the magical girl series DokiDoki! PreCure, he voiced the character Sebastian in the original Japanese version; this role carried over to the English-localized version, Glitter Force Doki Doki. His other significant voice roles include the Chancellor in Bibliophile Princess, Aleister in Arifureta: From Commonplace to World's Strongest, Hydra in Bakugan Battle Brawlers, and Jackie Washington in Tiger & Bunny 2. More recently, his voice work can be heard in series such as Heavenly Delusion, Ishura, and DAN DA DAN.

Oikawa has demonstrated recurring collaborations in his live-action career, frequently appearing with actors such as Takuma Taka, Yuriko Natori, and Kazuki Kosakai in various television projects. His achievements include a long and stable career spanning over four decades in both the acting and voice acting industries, with notable longevity in major franchises like One Piece.