Yann Sommer is a Swiss professional footballer who plays as a goalkeeper for Serie A club Inter Milan.

Sommer completed his apprenticeship at Basel, where he won the Swiss Super League on four consecutive occasions, before transferring to Borussia Mönchengladbach in 2014, where he remained for nine years. He also won the Swiss Challenge League and two Liechtenstein Football Cups while on loan to Vaduz.

Sommer has represented Switzerland at various age levels, including at under-16, -17, -19 and -21 levels. He made his Swiss U-16s debut on 26 August 2003, but the match ended in a 0–5 defeat against Germany. His U-17s debut was on 20 November 2003 in the 1–1 draw against England.

Sommer made his professional debut for the Swiss under-21s on 22 August 2007, as he was substituted in at half-time during the 2–1 away win against Belgium. He was goalkeeper and captain of the Swiss U-21 team which competed in the final tournament of the 2011 UEFA European Under-21 Championship, hosted by Denmark between 11 and 25 June 2011. The Swiss team reached the 2011 UEFA European Under-21 Championship Final on 25 June without conceding a goal, but lost 2–0 to Spain. This was Sommer's final match for the under-21s.

Sommer made his debut for the Switzerland senior side on 30 May 2012 at the Swissporarena, Lucerne, in a 0–1 defeat against Romania in a friendly match.

On 13 May, he was named in Switzerland's 23-man squad for the 2014 World Cup in Brazil, where he served as back-up goalkeeper to Diego Benaglio. Alongside Bundesliga colleagues Roman Bürki and Marwin Hitz, Sommer was one of three goalkeepers included in Switzerland's UEFA Euro 2016 squad. Sommer was Switzerland's first-choice goalkeeper, playing all four of the nation's matches. Sommer was unable to prevent Switzerland being eliminated by Poland in the round of 16, losing 5–4 on penalties, after a 1–1 draw. He was included in the Switzerland's 23-man squad for the 2018 World Cup and made his World Cup debut in the team's 1–1 draw with Brazil in the opening match of Group E. In May 2019, he played in 2019 UEFA Nations League Finals, where his team finished fourth. Sommer was included in the 26-man Swiss squad for the postponed UEFA Euro 2020. On 28 June 2021, Sommer saved a penalty from Kylian Mbappé during the penalty shoot-out, in which Switzerland won 5–4 against France in the round of 16, after a 3–3 draw. On 2 July 2021, he made eight saves in extra time alone against Spain in the Euro 2020 quarter-finals; however, Switzerland lost 1–3 on penalties, after a 1–1 draw. In 2022, Sommer was chosen to be a member of the Swiss squad for the 2022 FIFA World Cup. He was named Man of the Match in his team's opening group game against Cameroon, which his team won 1–0.

Sommer married Alina in August 2019, whom he began dating in 2016. Their daughter, Mila, was born on 4 November 2019.