The 2015–16 season was Arsenal's 24th season in the Premier League and 90th consecutive season in the top flight of English football. The club entered the season as the FA Cup holders, and participated in the Premier League, FA Cup, League Cup, Community Shield and the UEFA Champions League. Arsenal were favourites to get their first league title since 2004, having been league-leaders towards the New Year, but a loss of form which included successive defeats to Manchester United and Swansea City saw them lose ground on eventual winners Leicester City, although they recovered to get 2nd, their highest finish in 11 years. Arsenal's attempt of winning a third consecutive FA Cup was unsuccessful, losing to Watford at the quarter-final stage, as well as exiting in the League Cup fourth round to Sheffield Wednesday. In Europe, Arsenal recovered from a poor start to qualify for the knockout-stages, but they were defeated in both legs against Barcelona. The season covers the period from 1 July 2015 to 30 June 2016.
Review
August
Arsenal began their season with the Community Shield against local rival side Chelsea. The Gunners won the match 1–0, following a goal by Alex Oxlade-Chamberlain, who scored via a drive into the top corner. The trophy was Arsène Wenger's 15th in 18 years of being in charge of Arsenal, and presented Wenger with his first win against a side managed by José Mourinho after 13 attempts. Soon after, Arsenal began their 24th Premier League season at home to West Ham United, and inspired by the signing of goalkeeper Petr Čech, many believed Arsenal to be title contenders for the first time in 11 years. The club's solid pre-season form, however, fizzled out as they failed to win in their first two home games, with a 2–0 defeat to West Ham on the opening weekend, leaving them third-bottom, and a goalless draw with Liverpool, although Aaron Ramsey was falsely ruled offside for an early goal. With two tight wins at Crystal Palace and Newcastle United, Arsenal went into September with seven points. Arsenal did not make additional signings after Čech, leaving manager Wenger to come under fire from fans and critics.
September
Arsenal started September with a nervy 2–0 win over Stoke City at the Emirates, with Theo Walcott and Olivier Giroud scoring. Between the Stoke clash and a trip to struggling champions Chelsea, Arsenal faced Dinamo Zagreb away in the Champions League. Despite appearing the stronger side, Arsenal slumped to a shock 2–1 defeat, with under-performing striker Giroud being sent off for two yellow cards. The week got worse as Arsenal lost 2–0 at Stamford Bridge, with Santi Cazorla (two yellows) and Gabriel being sent off, the latter incorrectly shown red by Mike Dean for a clash with Diego Costa in which the latter assaulted Laurent Koscielny. Gabriel's ban was reduced from three games to one, but Gabriel, Costa, Chelsea and Arsenal were all fined for player misconduct, with Costa suspended for three games. With the Chelsea incident resolved, Arsenal faced a tough League Cup tie with North London arch-rival club Tottenham Hotspur at White Hart Lane. Mathieu Flamini became an unsung hero with a brace, the second of which was a volley from 20 yards, both goals on the other side of a Calum Chambers own goal. Arsenal, full of confidence after eliminating their rivals, visited the only unbeaten team in the league at the time, Leicester City, who were one point and one place above Arsenal. Despite a brace from Jamie Vardy, Walcott and Giroud scored either side of three goals from Sánchez, who ended a run of seven games without a goal. Arsenal ended their month on a sour note, however, as errors from second-choice goalkeeper David Ospina saw Arsenal lose 3–2 to Olympiacos at home in the Champions League, meaning they were bottom of their group with successive games against in-form Bayern Munich coming up.
October
Arsenal started October on a high, as three early goals—two from Alexis Sánchez and one from Mesut Özil—at the Emirates saw Arsenal breeze past Manchester United to leapfrog them into second place in the league table, behind Manchester City. Arsenal travelled to Vicarage Road two weeks later to play Watford, where goals from Sánchez, Aaron Ramsey and Olivier Giroud saw Arsenal claim another 3–0 win. Arsenal hosted German heavyweights Bayern Munich in an attempt to turn around their Champions League. Despite the German team losing only once all season, Arsenal claimed a shock 2–0 win, with Giroud and Özil scoring late in the second half. Giroud's return to form saw him return to the starting lineup ahead of Theo Walcott. Giroud thanked Wenger by inspiring the Gunners to a 2–1 win over Everton at the Emirates. Arsenal's only loss in October came between the Everton win and a 3–0 victory over Swansea City, courtesy of goals from Giroud, Laurent Koscielny and Joel Campbell, when they were stunned by Championship side Sheffield Wednesday, going out of the League Cup in a 3–0 defeat that saw Theo Walcott and Alex Oxlade-Chamberlain off injured, with goals from Ross Wallace, Lucas João and Sam Hutchinson.
November Arsenal were humiliated at the Allianz Arena to start November, with Bayern Munich cruising to a 5–1 win, putting Arsenal's Champions League progression in doubt. Arsenal hosted rivals Tottenham on the Sunday that followed, but with stars Héctor Bellerín, Theo Walcott, Aaron Ramsey and Alex Oxlade-Chamberlain on a list of ten injured Arsenal players, the Gunners had to struggle for a 1–1 draw. November only got worse for Arsenal, with Francis Coquelin looking at three months out, Mikel Arteta facing several weeks out after both were injured in a 2–1 defeat at West Bromwich Albion, with Santi Cazorla missing a vital penalty late on. Arsenal's Champions League form bounced back, with an Alexis Sánchez brace giving Arsenal a 3–0 win over Dinamo Zagreb at the Emirates. With Olympiacos thrashed by Bayern, Arsenal would need a two-goal cushion or a 3–2 or higher victory in Athens to progress. Arsenal's horrid month ended with more misery, with Sánchez and Cazorla both suffering injuries in a 1–1 draw with Norwich City, with Cazorla's keeping him out for three months. Oxlade-Chamberlain, Ramsey and Walcott, however, all returned at the end of the month, with the crucial Olympiacos game and a match with Premier League title contenders Manchester City coming up.
December Arsenal returned to form in December, starting with a 3–1 win over Sunderland, with Joel Campbell and Aaron Ramsey scoring either side of goals at either end from Olivier Giroud. Arsenal then traveled to Olympiacos, where they had failed to win in their last three games, with their last win in Greece coming in 1998. Fears were erased by a Giroud hat-trick, putting Arsenal through and demoting Olympiacos into the Europa League, only for Arsenal to draw holders Barcelona, who had knocked Arsenal out in the 2010 quarter finals and in 2011 at the same stage. The Spanish side also beat the Gunners in the 2006 final. Arsenal recorded successive victories before Christmas, winning 2–0 at Aston Villa, before a 2–1 home win over Manchester City. As things were looking up, a Boxing Day defeat at Liverpool saw surprise leaders Leicester loosen their grip on first, giving Arsenal a chance to go top with a win against Southampton, but a Shane Long brace saw Arsenal thrashed 4–0. Despite this, Arsenal still finished 2015 top of the Premier League, after a 2–0 win against AFC Bournemouth was enough to keep Arsenal ahead of Leicester on goal difference, who drew 0–0 with Manchester City in their final game of 2015.
January
Arsenal started 2016 with an unconvincing 1–0 win over relegation scrappers Newcastle, courtesy of a late Laurent Koscielny goal. Arsenal kicked off their FA Cup defence against Sunderland at the Emirates. Their 3–1 win mirrored the clash in December, with Joel Campbell, Olivier Giroud and Aaron Ramsey scoring Arsenal's goals in identical fashion to the league tie, despite an early Jeremain Lens goal. This was followed by two away league fixtures at Liverpool and Stoke; the former was a 3–3 draw with Giroud scoring a brace and Ramsey finding the net for Arsenal, whereas the latter finished scoreless. On 24 January, Arsenal hosted local rivals Chelsea and were defeated 1–0 after Per Mertesacker was sent off. This meant they had failed to win a league game against Chelsea for the ninth league meeting in a row, and it was the sixth consecutive time they had failed to score in the fixture. Six days later, Arsenal advanced to the fifth round of the FA Cup, with Calum Chambers and Alexis Sánchez scoring in a 2–1 defeat of Championship side Burnley at home. Arsenal made one signing in January, Basel's Egyptian midfielder Mohamed Elneny completed a £5 million move.
February
In the beginning of February, Arsenal failed to score for the third consecutive league match, playing Southampton to a stalemate at the Emirates. Mesut Özil and Alex Oxlade-Chamberlain led Arsenal back to winning ways with a 2–0 away victory at AFC Bournemouth. Arsenal then won a dramatic top of the table clash with league leaders Leicester, coming back after a Jamie Vardy penalty to win 2–1 at home, with late goals from Theo Walcott and Danny Welbeck, reducing the gap between Arsenal and Leicester in second and first to two points. Despite a dominant performance at home, Arsenal were held to a 0–0 draw by Hull City in the fifth round of the FA Cup. Arsenal subsequently returned to Champions League action by hosting title holders Barcelona. A Lionel Messi brace condemned Arsenal to a 2–0 defeat. Arsenal ended February with an away game at Manchester United, with goals from Welbeck and Özil not enough to avoid a 3–2 defeat.
March Arsenal started March suffering a third consecutive loss at the hands of Swansea at home; Joel Campbell's goal was cancelled out and the match finished 2–1 to Swansea. Arsenal then visited local rivals Tottenham in a make-or-break clash, as defeat would put Arsenal six points off their rivals, above Arsenal in second. Aaron Ramsey gave Arsenal a crucial lead, but a Francis Coquelin sending off for two yellow cards turned the game on its head. Toby Alderweireld and Harry Kane struck back to put Spurs ahead, but Alexis Sánchez helped the team rescue a point with a late goal, with the match finishing 2–2. Olivier Giroud and Theo Walcott scored two goals each against Hull City in the FA Cup fifth round replay to reach the quarter finals, but Arsenal went out after a 2–1 home defeat to Watford, with Danny Welbeck scoring the lone goal for the team as Arsenal's defence ended, after winning the previous two titles. Arsenal went out of their second cup competition just days later, being condemned to a sixth-straight last-16 elimination from the Champions League with a 3–1 away loss to Barcelona, Mohamed Elneny's first Arsenal goal proving a mere consolation. One promising note from the defeat was the performance of Nigerian youngster Alex Iwobi, and he was rewarded with his second Premier League start against Everton at the end of March. His first club goal, and a fourth goal in nine games since return for Danny Welbeck, saw Arsenal win 2–0.
April