| Honorific Prefix: | Dr |
| Jun-iti Nagata | |
| Native Name: | 長田潤一 |
| Native Name Lang: | Japanese |
| Nationality: | Japanese |
| Occupation: | Mathematician |
| Known For: | Nagata–Smirnov metrization theorem |
| Professor emeritus | |
| Education: | PhD |
| Alma Mater: | Osaka University |
| Doctoral Advisor: | Kiiti Morita |
| Discipline: | Topology mathematics |
| Workplaces: | Osaka Kyoiku University, Osaka Electro-Communication University |
| Notable Works: | Modern Dimension Theory, Modern General Topology |
was a Japanese mathematician specializing in topology.
In 1956, Jun-iti Nagata earned his PhD from Osaka University under the direction of Kiiti Morita. He was the author of two standard graduate texts in topology: Modern Dimension Theory[1] and Modern General Topology.[2] His name is attached to the Nagata–Smirnov metrization theorem, which was proved independently by Nagata in 1950 and by Smirnov in 1951, as well as the Assouad–Nagata dimension of a metric space, which he introduced in a 1958 article.[3]
Nagata became a professor emeritus at both Osaka Kyoiku University, where he taught for 10 years, and Osaka Electro-Communication University, where he taught for 5 years.