Go Nagai (永井 豪 Nagai Gō, born September 6, 1945) is a Japanese mangaka and an important innovator of several genres.

When he was 20 he created 'Kuro No Shishi' ('Black Lion'). In his series Harenchi Gakuen (ハレンチ学園, Shameless School, 1968-1972, Shonen Jump magazine) Nagai used eroticism and extreme, graphical violence in children's comics for first time in Japan thus breaking taboos and becoming quite controversial. Its use of violence and gross humour were also widely loathed in many corners of Japan's society. The series ended dramatically: all the characters died during a massacre. This type of content and story would be a trend in most of Nagai's later work.

In 1970, Go Nagai started a company, Dynamic Productions, to fund his manga and anime ventures. The first titles of DP were Getter Robo and Abashiri Ikka (あばしり一家, Abashiri Family).

After Harenchi Gakuen Nagai created the Mazinger Z (マジンガーZ, as well Majinga Z) series, later expanded to Great Mazinger and Mazinkaiser, where he developed the concept of giant mecha. This idea happened to be amazingly productive in many television programmes in his country. Mazinger is, in fact, considered the first successful "Super Robot" anime show, and has spanned numerous imitations, even today.

A few years later Go Nagai created Grendizer aka Goldorak (or Goldrake) in some countries. Grendizer was originally intended to cash in on the UFO craze that was en vogue in Japan during the late '70s; it became popular not only in Japan, but in European countries like France and Italy, and specially in the Arab world, where it was popular in 18 Arab countries, especially Egypt. Grendizer is still a household name today in this part of the world.

Simultaneously to Mazinger, he created one of his most popular series, Debiruman (デビルマン, Devilman), about a hero having spectacular fights against awesome hordes of demons. 'Debiruman' is a cult event in Japan. Go Nagai later revamped this popular series by introducing the main character as a female and altering the storyline. This series is called Devilman Lady (デビルマンレディー, Devil Lady in the U.S.). It was first released as a manga and then later as an anime just as Devilman. Go Nagai considers the Devilman series, as well as the Mazinger series, as being his life's work due to their massive popularity all over the world.

Despite its popularity, much of Go Nagai's work (due to its graphical nature, and treatment of subjects such as sex and violence) is little known in the US, where censorship has been the main factor.

Nagai has worked with Ishimori Shotaro and Ken Ishikawa . He is currently being more prolific in manga production than ever. Many of his manga series have anime versions.

Other series created by Go Nagai:

• Getter Robo (ゲッターロボ)
• UFO Robot Grendizer (UFOロボ グレンダイザー)
• Kotetsu Jeeg (鋼鉄ジーグ)
• Daikyu Maryuu Gaiking (大空魔竜ガイキング)
• Violence Jack (ヴァイオレンス ジャク)
• Cutey Honey (キューティーハニー)