As a member of the under-20 Brazil team, Willian made his debut in the 2007 South American Youth Championship against Chile on 7 January 2007, which Brazil went on to win.
In 2007, he was also selected for the FIFA U-20 World Cup, but Brazil were eliminated in the quarter-finals by Spain.

On 10 November 2011, Willian made his senior debut for Brazil in a friendly match against Gabon.
On 16 November 2013, he scored his first international goal in a 5–0 win over Honduras in Miami, Florida.

On 7 May 2014, Willian was selected as part of the 23-man squad for the 2014 FIFA World Cup.
He came on at half-time in extra time of the round of 16 match against Chile in Belo Horizonte for his Chelsea teammate Oscar, and took a penalty in the shootout which he put wide of the goal, although Brazil nonetheless advanced.

At the 2015 Copa América, Willian assisted Roberto Firmino's decisive goal in the 2–1 win over Venezuela in Santiago, a result which sent Brazil into the quarter-finals as group winners.

On 5 May 2016, he was named by Brazil manager Dunga among the 23-man list for the Copa América Centenario to be held in the United States.

In May 2018 he was named in Tite’s final 23-man squad for the 2018 FIFA World Cup in Russia.

On 7 June 2019, he received a late call-up for the 2019 Copa América to replace the injured Neymar.
As a member of the under-20 Brazil team, Willian made his debut in the 2007 South American Youth Championship against Chile on 7 January 2007, which Brazil went on to win. In 2007, he was also selected for the FIFA U-20 World Cup, but Brazil were eliminated in the quarter-finals by Spain.
On 10 November 2011, Willian made his senior debut for Brazil in a friendly match against Gabon. On 16 November 2013, he scored his first international goal in a 5–0 win over Honduras in Miami, Florida.
On 7 May 2014, Willian was selected as part of the 23-man squad for the 2014 FIFA World Cup. He came on at half-time in extra time of the round of 16 match against Chile in Belo Horizonte for his Chelsea teammate Oscar, and took a penalty in the shootout which he put wide of the goal, although Brazil nonetheless advanced.
At the 2015 Copa América, Willian assisted Roberto Firmino's decisive goal in the 2–1 win over Venezuela in Santiago, a result which sent Brazil into the quarter-finals as group winners.
On 5 May 2016, he was named by Brazil manager Dunga among the 23-man list for the Copa América Centenario to be held in the United States.
In May 2018 he was named in Tite’s final 23-man squad for the 2018 FIFA World Cup in Russia.
On 7 June 2019, he received a late call-up for the 2019 Copa América to replace the injured Neymar.
Willian (footballer, born 1988)