Yoshiyuki Sadamoto is a renowned Japanese character designer, manga artist, and one of the founding members of the Gainax anime studio. Born on January 29, 1962, in Tokuyama (now Shunan), Yamaguchi Prefecture, Japan, he is particularly known for his work as the character designer of the iconic anime series Neon Genesis Evangelion and its manga adaptation.

His other notable works include character designs for the .hack//Games and the package designer for the .hack//GU games. In addition to his professional work, he also publishes under the doujinshi pen name 45yen.