In the six seasons so far, only three teams have won the ISL, with the erstwhile ATK FC being the most successful team, having won the title three times.
In the 2019-20 season, apart from the champions, the ISL also awarded the league shield to the team that finished top of the league table. FC Goa became the first-ever recipients of the league shield, thereby also confirming their participation in the 2020-21 AFC Champions League. Goa will be the first Indian side to participate in the group stages of Asia's premier club competition.
In this article, we take a look at the champions from each edition of the ISL since 2014.
#1 ATK - 2014
ATK, then Atletico de Kolkata, became the first ever winners of the ISL, under head coach Antonio Lopez Habas.
They had finished third in the points table at the end of the league stages, four points behind table-toppers Chennaiyin FC. In the semifinal against FC Goa, the two sides were unable to be separated after 210 minutes of action over two legs, including extra-time.
Andre Santos and Zohib Islam Amiri missed their penalties in the shootout for Goa, to send ATK through to the final against Kerala Blasters.
The final, played at Mumbai's DY Patil Stadium, was a a cagey affair, and seemed set to be headed into extra-time, after Kerala Blasters had a few great chances saved by goalkeeper Apoula Edel Bete.
But in the 95th minute, ATK had a corner, and Mohammed Rafique stepped up to win them the match, with a superb near-post header.
Spaniard Luis Garcia became the first captain to lift the ISL trophy.
#2 Chennaiyin FC - 2015
Chennaiyin FC had to endure heartbreak in the first ISL season, when an extra-time goal from Stephen Pearson at the Marina Arena sent Kerala Blasters through at their expense.
However, Marco Materazzi's side came roaring back the very next year to complete the unfinished business from 2014.
Halfway through the season, Chennaiyin were in danger of not qualifying for the knockouts. But eventually, John Stiven Mendoza stepped up in their last few games to inspire them through to the knockout stages.
In the semifinal, the home leg of which they had to play in Pune due to floods in Chennai, Chennaiyin FC beat ATK 4-2 on aggregate, after a 3-0 win at the Balewadi Stadium.
The final lived up to the dramatic nature of ISL finals, with FC Goa looking set to clinch the trophy on home turf, when Jofre Mateu put them ahead with a free-kick in the 88th minute.
However, a Laxmikant Kattimani own-goal threw Chennaiyin a lifeline, before Mendoza stepped up to run on to a Jayesh Rane through-ball and slot past Kattimani to hand Chennaiyin the title.