Tetsuya Nishio (西尾 鉄也, Nishio Tetsuya, born 23 June 1968 in Aichi Prefecture) is a Japanese animator and character designer. He began his career in 1988 as an inbetween animator for the TV series Osomatsu-kun. He was affiliated with Studio Pierrot before joining Production I.G.

He is considered one of the "Three Gods of IG" along with Hiroyuki Okiura and Kazuchika Kise and was rewarded the Best Character Design Award at the 8th Tokyo Anime Awards in 2009 for his outstanding work on Sky Crawlers, where he designed the characters and was key animation supervisor.