2018 Liga 1

The 2018 Liga 1 (known as the GO-JEK Liga 1 with Bukalapak for sponsorship reasons) is the second season of Liga 1 and the ninth season of the top-flight Indonesian professional league for association football clubs since the establishment of Indonesian Super League in 2008. The season started on 23 March 2018 and is scheduled to finish on 9 December 2018.

Bhayangkara were the defending champions, while Persebaya Surabaya, PSMS Medan, and PSIS Semarang have entered as the promoted teams from the 2017 Liga 2.

The 1st transfer window is from 10 February 2018 to 5 April 2018 while the 2nd transfer window is from 5 July 2018 to 2 August 2018.

Player regulations
Player registration is divided into two periods. The first period opens from 10 February 2018 and closes on 5 April 2018. Then the second period is done on 5 July to 2 August 2018. Clubs can register at least 18 players and a maximum of 30 players. The club is also required to contract at least seven local U-23 players (born on or after 1 January 1996). Unlike last season, U-23 players are not required to play in one game.

Persija Jakarta and Bali United get privileges related to player quota. Both are allowed to add three local players with no age limit, following their participation in the 2018 AFC Cup representing Indonesia.

Referee
Unlike last season, the league operator ensure will not use foreign referees for this season.

Teams
Eighteen teams will compete in this season – the top fifteen teams from the previous season, as well as three teams promoted from the Liga 2.

Teams promoted to Liga 1

The first club to be promoted was Persebaya Surabaya, following their 3–1 win against Martapura in the first Liga 2 Semifinals match on 25 November 2017. Persebaya will play in the top flight of Indonesian football for the first time since their status as the member of PSSI reinstated in January 2017 after being banned due to playing in an illegal competition. They were crowned champions on 28 November 2017 after beating PSMS 3–2 on extra time after a 2–2 draw at regular time in the Liga 2 Final.

PSMS Medan became the second club to be promoted after beating PSIS Semarang 2–0 on extra time after a 0–0 draw at regular time in the second Liga 2 Semifinals match. PSMS will play in the top flight of Indonesian football for the first time since 2011–12 season.

The third and final club to be promoted was Liga 2 third-place play-off winners PSIS Semarang, who beat Martapura 6–4 on extra time after a 4–4 draw at regular time on 28 November 2017. PSIS will play in the top flight of Indonesian football for the first time since 2008–09 season.

Teams relegated to Liga 2

The first club to be relegated was Persegres Gresik United, ending their 5-year stay in the Liga 1 after a 2–4 home defeat to Mitra Kukar on 7 October 2017.

The second club to be relegated was Persiba Balikpapan, their 13-year tenure in Indonesian top flight coming to an end after a 3–4 home defeat to Madura United on 29 October 2017.

The third and final club to be relegated was Semen Padang, ending their 3-year stay in the Liga 1 despite a 2–0 home win against PS TNI on their last fixture. Their points can no longer pursue Perseru Serui which also win their last match against Persib Bandung.

Name changes

 * PS TNI was changed to PS TIRA after moving their base to Bantul in January 2018.

Stadium and Locations
PSIS Semarang use Moch. Soebroto Stadium as their home ground for this season because their regular home ground, Jatidiri Stadium is being renovated and will not be completed until 2019. But they use Sultan Agung Stadium, Bantul to host the team with big supporter.

PS TNI changed their name to PS TIRA and moved their home base from Pakansari Stadium, Cibinong to Sultan Agung Stadium, Bantul.

Bhayangkara moved their home base from Patriot Candrabaga Stadium, Bekasi to PTIK Stadium, Jakarta. But until April 2018 and when they hosting teams with large supporter, they use Gelora Delta Stadium, Sidoarjo because PTIK Stadium is being renovated.

Perseru Serui will temporary use Gajayana Stadium, Malang as their home ground during Ramadan because Marora Stadium didn't pass verification to held a match at night.

Persija Jakarta will play outside Jakarta (Gelora Bung Karno Stadium) because the stadium are being prepared for the 2018 Asian Games opening ceremony and should be sterilized. They will temporary use Sultan Agung Stadium, Bantul. At the end of September, they will play at Patriot Candrabaga Stadium, Bekasi.

Personnel and kits
Note: Flags indicate national team as has been defined under FIFA eligibility rules. Players and coaches may hold more than one non-FIFA nationality.

Foreign players
Football Association of Indonesia restricted the number of foreign players to four per team, including one slot for a player from AFC countries. Teams can use all the foreign players at once.

Discipline

 * Most yellow card(s): 7
 * Marc Klok (PSM)
 * Most red card(s): 2
 * Agus Nova Wiantara (Bali United)
 * Leonard Tupamahu (Borneo)