Larsson received his first call-up to the Sweden squad for the UEFA Euro 2008 qualifying games against Liechtenstein and Northern Ireland in October 2007.
He was an unused substitute against Liechtenstein but did not make the bench for the Northern Ireland game.
He made his debut for Sweden in February 2008, playing the whole 90 minutes of a friendly draw against Turkey in Istanbul.
He was named in Sweden's 23-man squad for UEFA Euro 2008, and has since become a regular in the national team.

He scored his first goal at senior international level in March 2011 as Sweden beat Moldova 2–1 in a Euro 2012 qualifier.
During the qualifiers in October, Larsson added two more goals to his international tally.
The first was the opener in a 2–1 away victory over Finland in Helsinki, and the second was a penalty as Sweden came from behind to beat the Netherlands 3–2 on 11 October at the Råsunda Stadium in Stockholm.
In February 2012, Larsson scored two second-half goals to down Croatia 3–1 at the Maksimir Stadium in Zagreb.

Larsson was selected in Sweden's squad for Euro 2012.
He started all three of their group games and scored the second goal in their 2–0 win over France, but Sweden did not make it through to the knockout stages of the competition.

He was named in Sweden's 23-man squad for the 2018 World Cup in Russia.
In the last warm-up match before the tournament, a goalless draw with Peru on 9 June, he made his 100th senior appearance for his country.
At the 2018 World Cup, Larsson played in 4 games for Sweden as they were eliminated by England in the quarter final.
Larsson received his first call-up to the Sweden squad for the UEFA Euro 2008 qualifying games against Liechtenstein and Northern Ireland in October 2007. He was an unused substitute against Liechtenstein but did not make the bench for the Northern Ireland game. He made his debut for Sweden in February 2008, playing the whole 90 minutes of a friendly draw against Turkey in Istanbul. He was named in Sweden's 23-man squad for UEFA Euro 2008, and has since become a regular in the national team.
He scored his first goal at senior international level in March 2011 as Sweden beat Moldova 2–1 in a Euro 2012 qualifier. During the qualifiers in October, Larsson added two more goals to his international tally. The first was the opener in a 2–1 away victory over Finland in Helsinki, and the second was a penalty as Sweden came from behind to beat the Netherlands 3–2 on 11 October at the Råsunda Stadium in Stockholm. In February 2012, Larsson scored two second-half goals to down Croatia 3–1 at the Maksimir Stadium in Zagreb.
Larsson was selected in Sweden's squad for Euro 2012. He started all three of their group games and scored the second goal in their 2–0 win over France, but Sweden did not make it through to the knockout stages of the competition.
He was named in Sweden's 23-man squad for the 2018 World Cup in Russia. In the last warm-up match before the tournament, a goalless draw with Peru on 9 June, he made his 100th senior appearance for his country. At the 2018 World Cup, Larsson played in 4 games for Sweden as they were eliminated by England in the quarter final.
Sebastian Larsson