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.

In January 2017, the JRFU announced that the Top League competition would be held earlier in the year, in order to aid the Japanese Super Rugby franchise the Sunwolves' preparations for the following season.

The title play-offs will also double as the All-Japan Rugby Football Championship, which would no longer include university teams.

The final standings for the 2017–18 Top League are: The title play-offs also double up as the 55th All-Japan Rugby Football Championship.

Coca-Cola Red Sparks and Munakata Sanix Blues retained their places in the Top League for 2018–19, with the former drawing against Mitsubishi Sagamihara DynaBoars and the latter beating Kyuden Voltex.