In the 2017–18 season, Minamino started the season well when he scored three goals in three different competitions against Hibernians, Deutschlandsberger SC and Wolfsberger AC. However, during a 5–1 win over St. Pölten on 20 August 2017 (which he set up the club's first goal of the game), Minamino suffered a ligament tear and was substituted in the 40th minutes; and as a result, he was sidelined for six weeks). It wasn't until on 14 October 2017 when he made his return, coming on as a late substitute, in a 3–1 win over LASK. Minamino then scored his first goals in three months, in a 3–1 win over St. Pölten on 5 November 2017 and three weeks later on 29 November 2017, he scored again, in a 2–0 win over SV Mattersburg. At the beginning of February, Minamino signed a contract extension with the club, keeping him until 2021. He later scored three more league goals for the side, including a brace against Austria Wien on 18 March 2018. Minamino later helped Red Bull Salzburg win the league for the fourth consecutive time in his Red Bull Salzburg career. During the 2017–18 season, Salzburg had their best ever European campaign, as they finished top of their Europa League group, for a record fourth time, before beating Real Sociedad, Borussia Dortmund and Lazio (in which he scored two goals in the knockout stage against Real Sociedad and Lazio), thus making their first ever appearance in the UEFA Europa League semi-final. On 3 May 2018, he played in the Europa League semi-finals as Olympique de Marseille played out a 1–2 away loss but a 3–2 aggregate win to secure a place in the UEFA Europa League Final. By the end of the 2017–18 season, Minamino had made 44 appearances and scored 11 goals in all competitions.