1966 Japan Soccer League
The 1966 season of the Japan Soccer League.
League tables
Promotion/relegation Series
Nagoya Mutual Bank became the first original JSL club to be relegated. In its place, Nippon Kokan from Kawasaki, Kanagawa was promoted and began a long career of league success that was only brought to a halt by the professionalization of the league.| JSL | 1st leg | 2nd leg | Senior Cup |
| Nagoya Mutual Bank | 2-3 | 1-2 | Nippon Kokan |
| Yanmar Diesel | 1-0 | 1-1 | Urawa SC |
Nippon Kokan promoted, Nagoya Mutual Bank relegated.