Original Puma Arsenal 2017/18 training jersey

The 2017–18 season was Arsenal's 26th in the Premier League and 98th 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.