2017–18 Top League
| 2017–18 Top League | |
|---|---|
Crowd at the 2017–18 final for the 55th All-Japan title | |
| Countries | Japan |
| Date | 18 August 2017 – 14 January 2018 |
| Champions | Suntory Sungoliath (5th title) |
| Runners-up | Panasonic Wild Knights |
| Relegated | Kintetsu Liners, NTT DoCoMo Red Hurricanes |
| Matches played | 120 |
| Attendance | 640,685 (average 5,339 per match) |
| Highest attendance | 27,871 (Toyota Verblitz v Yamaha Júbilo, Round 1) |
| Lowest attendance | 1,107 (Kubota Spears v Canon Eagles, 9th-place play-off) |
| Top point scorer | Lionel Cronjé (132) |
| Top try scorer | Akihito Yamada (12) |
The 2017–18 Top League was the 15th season of Japan's top-tier domestic rugby union competition, the Top League.
The tournament was won by Suntory Sungoliath for the fifth time, beating Panasonic Wild Knights 12–8 in the final played on 13 January 2018. Kintetsu Liners were automatically relegated to the second-tier Top Challenge League competition for 2018 and NTT DoCoMo Red Hurricanes were also relegated after losing in their relegation play-off match.