Atlético de Kolkata entered the 2015 season as the first defending champions of the Indian Super League. Their title defense began on 3 October 2015 against Chennaiyin. A brace my new marquee, Hélder Postiga, helped Atlético de Kolkata win the match 3–2. They would go on the finish the regular season in second place, two points behind first place Goa. They would enter the finals facing off against Chennaiyin again. A 3–0 victory by Chennaiyin in the first leg all but sealed the fate for Kolkata, which was confirmed after Atlético de Kolkata could only manage a 2–1 victory in the second leg.
