Midfielder Michael Collins was signed a couple weeks after the start of the I-League season as an injury replacement to Josh Walker.

Indian youth internationals Amrinder Singh and Seiminlen Doungel were also brought in by Westwood, alongside young prospects Daniel Lalhlimpuia, Malsawmzuala, and Nishu Kumar from the AIFF Elite Academy.

Bengaluru's Asian campaign began slowly with two defeats to open the group stage, but three victories in a row helped push the club to finish second in the table.

Amrinder Singh was awarded as the best goalkeeper, John Johnson as best defender, Eugeneson Lyngdoh as best midfielder, and Ashley Westwood as best coach.

Despite having the home advantage and taking the lead before halftime through John Johnson, Mohun Bagan defender Bello Razaq managed to score an 87th minute equalizer and help his side to a 1–1 draw.

[8] Westwood also commented on the upstart Indian Super League and the disruption to the I-League season stating "We've had two years to prepare for the ISL.

"[8] As soon as the previous season ended, it was announced that Sean Rooney would be leaving the club to sign with Oakleigh Cannons in Australia.

[9] Also let go were goalkeeper Pawan Kumar, midfielders Darren Caldeira and Malemngamba Meitei, and forward Karan Sawhney after their contracts expired.

[11] Bengaluru made their first signings of the season on 3 June 2015, bringing in North Korean forward Kim Song-yong from Royal Wahingdoh and midfielder Seiminlen Doungel from Shillong Lajong.

[12] It was then announced two days later on 5 June that the club had extended the contracts of 10 players: Eugeneson Lyngdoh, Josh Walker, Shankar Sampingiraj, Rino Anto, Lalchhuanmawia, Udanta Singh, Lalthuammawia Ralte, C. K. Vineeth, Beikhokhei Beingaichho, and Siam Hanghal.

[14] In October 2015, Bengaluru signed Indian youth international defender Salam Ranjan Singh on loan from Pune.

[15] The next month, the club completed the triple signing of youth internationals Nishu Kumar, Malsawmzuala, and Daniel Lalhlimpuia from the AIFF Elite Academy.

In the second half, Sunil Chhetri converted the free-kick into the goal in 61st minute and Bengaluru FC won the game 2–1, registering their sixth consecutive win against Salgaocar in all competitions.

[30] In the next away game against Mumbai F.C., Bengaluru quickly conceded the lead as Arata Izumi and Son Min-chol scored a goal each within 11 minutes.

Bengaluru FC finished the game 4–1 with two more goals in the second half from substitutes Shankar Sampingiraj and Seminlen Doungel, and reclaimed the top spot.

Man of the match Udanta Singh scored his first ever goal in the I-League and gave Bengaluru FC the lead in the 36th minute.

After series of missed chances and almost a penalty, the substitute Daniel Lalhlimpuia broke the deadlock in 81st minute and Bengaluru FC registered their first ever win against the Mumbai team.

Returning from his injury Eugeneson Lyngdoh, gave the lead to the visitors in 34th minute from Sunil Chhetri's free kick, but 3 minutes later, Aser Pierrick Dipanda equalized and the score remained unchanged till the end of the game and Bengaluru FC remained in second position behind Mohun Bagan based on head-to-head record, with an extra game in the hand.

After starting aggressively, Bengaluru FC made a mistake in the midfield and Do Dong-hyun gave the lead to East Bengal in 27th minute.

Seminlen Doungel sealed the game in 87th minute when taped Sunil Chhetri's pass in the net and Bengaluru FC registered seventh straight win against the Goan club and also won 2015–16 I-League title with one round to go.

Ashley Westwood fielded the reserve side and Bengaluru FC faced massive 5–0 defeat in the inconsequential game.

A defensive lapse by Curtis Osano and an excellent free-kick just outside the penalty box from Phatthana Syvilay meant that Bengaluru were trailing by 2–0 at the 30 minutes mark.

[51] Injury-ridden Bengaluru FC faced defending AFC cup champions Johor Darul Ta'zim at home.

The game was decided by a solitary goal from Mohd Safiq Rahim in 55th minute and Bengaluru succumbed to second consecutive defeat in the AFC cup.

In what turned out to be the highest scoring match involving Bengaluru FC, the home team won the game 5–3 in spite of missed chances and defensive blunders.

Bengaluru FC faced Hong Kong team Kitchee SC, the group F winner, in the single-legged round of 16 game at the Mong Kok Stadium.

After conceding early lead in 7th minute, Bengaluru FC came back strong and Sunil Chhetri scored two goals in succession.

Even though Bengaluru FC missed a few easy chances in the second half, they managed to hold on to the lead and entered quarter-finals for the first time,[57] played during 2016–17 season.

Aizawl struck the final blow in the dying minutes when Joel Sunday scored the winner for the home team, leaving Bengaluru FC trailing after the first leg.

Vineeth's first half equalizer and Sunil Chhetri's successful penalty proved insufficient as Bengaluru FC were ousted from the Federation cup on 3–5 aggregate loss.