The 2018 Nadeshiko League Division 1 was the 29th season of the Japanese women's soccer league under this name. The regular season began in March and ended in October 2018. This was followed by the relegation games. The defending champion was NTV Beleza.
Relegation games against the vice-champions of Division 2
Relegation to Division 2 2019
At the end of the 2017 season:
(M)
Acting master: NTV Beleza
(R)
Relegation game winner: Cerezo Osaka
(N)
Newcomers from the Nadeshiko League Div. 2 2017: Nippon Sport Science University Fields Yokohama
Relegation to the Nadeshiko League Division 1
The penultimate of the Nadeshiko League Division 1 2018 competed against the 2nd placed Nadeshiko League Division 2 2018 for the relegation . The winner qualified for the Nadeshiko League Division 1 2019 .