The 2018–19 Top League was the 16th season of Japan's top-tier domestic rugby union competition, the Top League.
Competition rules
The sixteen Top League teams were divided into two conferences for the first stage of the competition; each team played the seven other teams in their conferences once.
All sixteen teams then progressed to a play-off stage; the top four teams in each conference advanced to the title play-offs and the bottom four teams in each conference to the 9th-place play-offs, which determined the final positions for the season. The title play-offs doubled up as the All-Japan Rugby Football Championship, which would no longer include university teams. The bottom four teams in the 9th-place play-off all played in relegation play-off matches.
Teams
The following teams took part in the 2018 Top League competition:
Honda Heat won the 2017–18 Top Challenge League to win promotion back to the Top League after a one-season absence. Hino Red Dolphins won their promotion play-off match to win promotion to the Top League for the first time in their history.
First Stage : Red Conference
Standings
The current standings for the 2018 Top League First Stage Red Conference are:
Matches
The 2018 Top League First Stage Red Conference fixtures are:
Round 1
Round 2
The match between Kobelco Steelers and Munakata Sanix Blues scheduled for Round 2 was postponed following the Hokkaido Eastern Iburi earthquake and was rescheduled for 29 September.
Round 3
Round 4
Round 2 (rescheduled)
Round 5
Round 6
Round 7
First Stage : White Conference
Standings
The current standings for the 2018 Top League First Stage White Conference are:
Matches
The 2018 Top League First Stage White Conference fixtures are:
Round 1
Round 2
Round 3
Round 4
Round 5
Round 6
Round 7
Second stage
Standings
The final standings for the 2018 Top League were:
Title play-offs
The four quarter final winners qualified for the semi-finals, while the losers qualified for the 5th-place semi-finals.
The two semi-final winners qualified for the final, while the losers qualified for the 3rd-place match. The two 5th-place semi-final winners qualified for the 5th-place match, while the losers qualified for the 7th-place match.
The final matches determined the final standings.
9th-place play-offs
The four 9th-place quarter final winners qualified for the 9th-place semi-finals, while the losers qualified for the 13th-place semi-finals and the relegation play-offs.
The two 9th-place semi-final winners qualified for the 9th-place final, while the losers qualified for the 11th-place match. The two 13th-place semi-final winners qualified for the 13th-place match, while the losers qualified for the 15th-place match.
The final matches will determine the final standings.