The 2025–26 Liga 1 (also known as the 2025–26 BRI Liga 1 for sponsorship reasons) will be the 9th season of Liga 1 under its current name and the 16th season of top-flight Indonesian football professional league since its establishment in 2008. The season is scheduled to begin on 1 August 2025 and conclude on 10 May 2026, which includes a period of break from 7 to 19 December 2025 in conjunction with the upcoming SEA Games in Thailand.
The summer transfer window will open on 24 June 2025 and close on 11 September 2025, while the winter transfer window will run from 2 January to 29 February 2026. 
Persib are the two-time defending champions having won their 2nd Liga 1 title, and 9th top flight title, the previous season.
Overview.
Promotion and relegation (pre-season).
18 teams will compete in the league – the fifteen teams from the previous season and three teams promoted from Liga 2.
Teams relegated to Liga 2.
PSIS became the first team to be relegated on 11 May 2025 after Semen Padang draw with Persebaya in an away match during matchweek 32. The result ended PSIS's seven seasons stay at top tier.
The last two teams to be relegated on 24 May 2025 were PSS and Barito Putera with the results of each match in final matchweek. Despite winning over Madura United, the result was not enough to save them from relegation and ended PSS's six seasons stay at top tier. Meanwhile, Barito Putera's victory over PSIS was also not enough to save them from relegation and ended their 11-seasons stay in the top tier, as in another match Semen Padang managed to win over Arema in an away match.
Teams promoted from Liga 2.
On 12 February 2025, Bhayangkara Presisi became the first team to secure promotion to Liga 1 after achieving a goalless draw against Persijap in matchweek 5 of Group Y in the championship round. Bhayangkara Presisi returned to the top tier after a one-season absence.
PSIM became the second team to be promoted on 17 February 2025 after defeating PSPS in matchweek 6 of Group X in the championship round. This season marks PSIM's return to the top tier after 18 seasons of absence and for the first time since the formation of Liga 1 (formerly known as the Indonesian Super League) in the 2008–09 season.
Persijap became the third and final team to be promoted on 25 February 2025 after defeating PSPS in the promotion play-off. This marked Persijap's return to the top tier after 10 seasons of absence, including two seasons in the third tier.
Teams.
Changes.
The following teams changed division since the 2024–25 season.
Locations and stadiums.
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Notes:
Foreign players.
Starting from last season, Liga Indonesia Baru announced an increase in the foreign player quota to eight foreign players.
 Capped for Indonesia national team.
 Capped for Indonesia national football team age groups (U-17, U-20, and U-23)
 Carrying Indonesia heritage.
Results.
Results by round.
Notes: