On 24 February 2021, Musiala announced he had decided to represent his birth nation, Germany, for full international matches. He subsequently received his first call up to the senior team for 2022 FIFA World Cup qualifiers in March 2021, making his debut on 25 March 2021 as a 79th minute substitute in a 3–0 win against Iceland. On 19 May 2021, he was selected to the squad for the UEFA Euro 2020. On 23 June 2021, he became the youngest German player to feature in a major tournament in a 2–2 draw with Hungary in Euro 2020, aged 18 years and 117 days.