| Tadahiro Aizawa | |
| Birth Date: | 21 June 1926 |
| Othername: | 相沢 忠洋 |
| Occupation: | merchant, an amateur archaeologist |
was a Japanese archaeologist. Aizawa, an amateur stone tool collector who had been peddling nattō, discovered a microlith in Iwajuku, Gunma in 1946, which was recognized in 1949 as a Paleolithic site that had previously been thought not to exist in Japan.