Sané made his senior international debut for Germany in November 2015 and was part of their squad that reached the semi-finals of UEFA Euro 2016.

[6] He is the son of former German rhythmic gymnast and 1984 Summer Olympics bronze medalist Regina Weber, and former footballer and Senegalese international Souleymane Sané.

Sané's two brothers, Kim and Sidi, have played for the youth side or second XI of major German football clubs.

[13] On 11 March 2015, Sané scored in his first UEFA Champions League match in a 4–3 victory over Real Madrid, although his side were knocked out of the competition on 5–4 aggregate.

[19] Following a spell on the sidelines due to injury, Sané made his return in a game against Tottenham Hotspur and scored in the 2–2 draw at the City of Manchester Stadium on 21 January 2017.

[24] On 15 March, Sané scored in the return fixture of the Champions League tie against Monaco; however, City lost 1–3, knocking them out from the tournament on away goals.

Although this caused him to miss that year's FIFA Confederations Cup, he said his chronic nasal congestion was becoming increasingly unbearable for him and that he wished to enter the next season feeling happy and healthy.

[43] Sané was voted the PFA Young Player of the Year for his part in Manchester City's 2017–18 Premier League title win, edging teammates Raheem Sterling and Ederson, as well as Tottenham Hotspur's Harry Kane.

[44][45][46] With 15 assists, Sané just missed out on winning the inaugural Premier League Playmaker of the Season award to teammate Kevin De Bruyne.

[52] On 21 February 2019, Manchester City were 2–1 down in the first leg of the Champions League round of 16 tie against Sané's former club, Schalke, playing with only 10 men after Nicolás Otamendi was sent off on the 68th minute.

[59] Despite a deal to the German side reportedly being nearly finalized, Sané was named in the starting 11 against Liverpool in the FA Community Shield.

After only 10 minutes, Sané was substituted after sustaining a torn ACL, ruling him out for the majority of the season and ending talks with Bayern until his injury healed.

[65] On 3 November 2020, Sané scored his first Champions League goal for Bayern Munich in a 6–2 away win over Red Bull Salzburg in the 2020–21 season.

[72] Sané was first called up to the Germany under-21 team by youth coach Horst Hrubesch on 28 August 2015 for the friendly against Denmark and for the 2017 UEFA European Under-21 Championship qualifier against Azerbaijan.

[73] On 3 September 2015, he made his debut for the German U21 side in a 2–1 win at Stadion an der Lohmühle in Lübeck against Denmark, where he was replaced after 73 minutes by Julian Brandt.

[10] On 13 November 2015, he was substituted in the 61st-minute for Julian Draxler in a friendly match against France in Saint-Denis in a 2–0 defeat for the Germans that was overshadowed by shootings and explosions around the stadium.

[78] Sané was omitted from Germany's final 23-man squad for the 2018 FIFA World Cup in favour of another young player, Julian Brandt, on 4 June 2018.

[79] In September 2018, after he was selected for the squad to face games against France and Peru, he left the team hotel after a discussion with Joachim Löw, citing "personal reasons" as his cause for leaving.