The 2017–18 season was Arsenal's 26th in the Premier League and 92nd consecutive season in the top flight of English football. The club participated in the Premier League, the FA Cup (as holders), the EFL Cup, the FA Community Shield and the UEFA Europa League.
This was the first season that Arsenal did not participate in the UEFA Champions League since 1997–98. It was the first time they had played in the UEFA Europa League since its rebranding, having last participated in the 1999–2000 UEFA Cup. A relatively poor season saw Arsenal fail to maintain a consistent challenge for Champions League qualification, with their away form being a major factor, only winning four away games in the league all season with 11 defeats, and they were, until the final game of the season, the only team in England's top 4 divisions to not get a point away from home in the 2018 calendar year. A total of 13 defeats were recorded throughout the league campaign, the highest since the 1994–95 season, which resulted in a 6th-place finish. Furthermore, a shock 4–2 defeat at Nottingham Forest meant that Arsenal were knocked out of the FA Cup third round for the first time since 1996.
Arsenal were runners-up in the League Cup, being defeated 3–0 in the final against Manchester City. Arsenal were close to winning their first European trophy since the Cup Winners' Cup in 1994, but a 2–1 defeat on aggregate against Atlético Madrid in the semi-finals resulted in another season in the Europa League.
The season was the 21st straight and final season under manager Arsène Wenger, who announced his departure from the club on 20 April 2018. This season covered the period from 1 July 2017 to 30 June 2018.
Background Arsenal's announced their first summer signing, Sead Kolašinac, on 6 June 2017. The left-back arrived on a free transfer when his contract at Schalke 04 expired. He was joined by Alexandre Lacazette just under a month later, who joined from Lyon for a reported club-record fee of £46.5 million on 5 July. Arsenal's first January transfer window signing was Greek defender Konstantinos Mavropanos from PAS Giannina, while acquiring Armenian international Henrikh Mkhitaryan in a swap-deal with Alexis Sánchez on 22 January 2018. The club then reunited Mkhitaryan with former teammate Pierre-Emerick Aubameyang in a club-record deal worth £56.0 million on 31 January.
Arsenal released Yaya Sanogo, Stefan O'Connor, Kostas Pileas and Kristopher Da Graca on 9 June 2017. Sanogo's four-year stay only included 11 league appearances for the club, while O'Connor, Pilea and Da Graca never appeared for the first team. Academy product Chris Willock joined Benfica on June 30 upon the expiry of his contract, signing a five-year deal. Kaylen Hinds, another academy product, departed the club on 8 July, joining Wolfsburg for £2.5 million on a three-year deal. Additional reserve players Glen Kamara and Daniel Crowley also departed the club, joining Dundee and Willem II respectively. Wojciech Szczęsny, who amassed over 150 appearances for the club during an eight-year stay, joined Italian champions Juventus for £10.0 million after his two-year loan at Roma expired. Meanwhile, club mainstay Kieran Gibbs departed for West Bromwich Albion for a £7.0 million fee, leaving after recording 230 appearances over 11 seasons. On deadline day, Alex Oxlade-Chamberlain, who was in the final year of his contract at the club, transferred to Liverpool for a record sale fee of £35.0 million and Donyell Malen returned to the Netherlands to join PSV Eindhoven. In the January window, Arsenal allowed the departures of many first-team players, including Theo Walcott and Francis Coquelin, who left for combined fees of £32.0 million. Moreover, Alexis Sánchez departed to Manchester United in a swap-deal which saw Henrikh Mkhitaryan arrive at the Emirates, while also sanctioning the departures of French first-team pair Olivier Giroud and Mathieu Debuchy, while academy product Marcus McGuane joined Barcelona. All in all, 22 players departed the club.
Takuma Asano had his season-long loan at Stuttgart from the previous season extended for an additional year. Marc Bola later joined Bristol Rovers on a season-long loan. About three weeks later, Emiliano Martínez left for Getafe and Stephy Mavididi went to Preston North End. Meanwhile, English full-back pair Carl Jenkinson and Cohen Bramall were loaned to Birmingham City, while reserve player Kelechi Nwakali departed to join Eredivisie outfit VVV-Venlo. On deadline day, fringe players Lucas Pérez and Joel Campbell, who have compiled 34 domestic appearances collectively, joined Spanish outfits Deportivo La Coruña and Real Betis respectively. In January, Stephy Mavididi had his loan cut short from Preston North End and, for the second time, was then loaned out to Charlton Athletic. English duo Tafari Moore and Ben Sheaf were then loaned out to fourth-tier sides Wycombe Wanderers and Stevenage, respectively, while four additional loans were completed on deadline day. Reserve pair Julio Pleguezuelo and Krystian Bielik joined Gimnàstic Tarragona and Walsall, while fringe first-team players Chuba Akpom and Jeff Reine-Adélaïde were also loaned out to conclude Arsenal's transfers for the season.
Review
July Arsenal took a 25-man squad to play in Australia. The squad included seven under-23s, including Reiss Nelson and Joe Willock, plus both new signings Sead Kolašinac and Alexandre Lacazette. The first match was on 13 July, which was a 2–0 win over Sydney FC, where captain Per Mertesacker scored an overhead kick and Lacazette scored a debut goal after coming on as a substitute. Two days later, Arsenal faced a second Sydney side, Western Sydney Wanderers, in front of 83,000 people. Arsenal won 3–1 after first-half goals from Olivier Giroud, Aaron Ramsey and Mohamed Elneny. Arsenal then travelled to China to face Bayern Munich in Shanghai in the International Champions Cup. Alex Iwobi scored an equalizer in the dying seconds of the match, which Arsenal would win on penalties 3–2. The 25-man squad travelled up to Beijing to face Premier League rivals Chelsea. The Blues won rather convincingly, scoring three times. On 29 and 30 July, the Emirates Cup was held. Arsenal, Benfica, RB Leipzig and Sevilla all took part in the tournament, which Arsenal won after a 5–2 win over Benfica, but a 2–1 loss to Sevilla. Over the tournament, Theo Walcott was the top scorer with two goals, both against Benfica. Giroud and Iwobi also scored one each against Benfica, while Lacazette scored one against Sevilla.
August Arsenal concluded their pre-season in the Community Shield, the traditional curtain raiser in English football. New signing Alexandre Lacazette hit the post on his competitive debut in a first half that saw Per Mertesacker replaced after a facial injury, with new signing Sead Kolašinac making his competitive debut as Mertesacker's replacement. After an end to the first half that yielded no goals, Chelsea took an early second half lead through Victor Moses, his close-range strike coming from a poorly defended corner. Several saved shots made it appear Arsenal were going to suffer defeat, until a rash challenge by Chelsea winger Pedro saw him sent off. The resulting free-kick was headed in by Kolašinac for a debut goal, and forced a penalty shootout. Arsenal were victorious 4–1 through goals by Theo Walcott, Nacho Monreal, Alex Oxlade-Chamberlain and Olivier Giroud, with Thibaut Courtois and Álvaro Morata missing penalties in the shootout that introduced the ABBA format. The result secured Arsenal's third FA Community Shield in four seasons.
Arsenal began their Premier League campaign at home to Leicester City, with the Gunners having lost their last two openers, both at home to West Ham and Liverpool. The record looked to be extended when Jamie Vardy and Shinji Okazaki scored for the Foxes after a record equaling 94th-second opener from new signing Lacazette, opening his league debut with his first competitive Arsenal goal with only his second touch of the game. Danny Welbeck drew Arsenal level in the last minute of first-half stoppage time, but Vardy scored a second ten minutes into the second half to put Leicester ahead once more. The Gunners looked set to lose their first match to the Foxes since 1994 when the final ten minutes approached, but a five-minute period of pressure yielded two goals from Aaron Ramsey and Olivier Giroud to make it 4–3, which the Gunners held on to for only their second opening day victory since 2012.
However, Arsenal's form slipped as August began to end. They suffered a 1–0 defeat against Stoke City after a poor defensive performance and a controversially disallowed goal from Alexandre Lacazette. The poor defence form continued as they were crushed 4–0 by Liverpool and failed to register a single shot on target, sending them near the relegation zone, despite the returns of suspended defender Laurent Koscielny and injured forward Alexis Sánchez.
September Arsenal began September with a 3–0 win over Bournemouth at home in the Premier League. Danny Welbeck scored either side of Alexandre Lacazette for an emphatic win. Five days on the Gunners would play in the Europa League having failed to secure a place for the usual Champions League. They played at home to German minnows FC Cologne and horrendously conceded a 40-yard goal as an unfortunate consequence of a mistake by second choice goalkeeper David Ospina thus were booed off the pitch at half time. However, Arsenal responded in the second half. Sead Kolašinac volleyed in the equaliser then Alexis Sánchez scored to give the Gunners the lead and Héctor Bellerín added a third as the match ended 3–1 in Arsenal's favor. Moreover, the match saw Jack Wilshere return for his first Gunners appearance in over a year. On 17 September Arsenal resumed the Premier League campaign as they played against champions Chelsea at Stamford Bridge. The match ended 0–0 despite Aaron Ramsey hitting the post and Chelsea defender David Luiz being sent off on 87 minutes. Three days later Arsenal played in the League Cup third round against League One team Doncaster Rovers at the Emirates. Theo Walcott scored the only goal of the match to send the Gunners into the fourth round but it was an unconvincing performance by Arsenal as they only managed a 1–0 win over a third-tier team. On 25 September Arsenal were at home to West Bromwich Albion in the Premier League. The Gunners won 2–0 with Lacazette scoring both goals. To end September Arsenal played the second Europa League match of this season. They took the trip to Belarus and won 4–2 against BATE Borisov. Walcott scored two before a first Arsenal goal for Rob Holding as well as Olivier Giroud's 100th goal for Arsenal as the Gunners took those three points to England.
October