After just one season at Arsenal, Willian agreed to tear up his contract despite it having two years remaining in London, having signed from rivals Chelsea on a three-year deal in 2020.
Following the confirmation of Willian's Arsenal departure by mutual consent in anticipation of a Sao Paulo homecoming, Corinthians announced the 33-year-old's arrival.
"I want to thank the fans for their affection, too," Willian – a two-time Premier League champion – said. "I'm getting a lot of messages. I'll do everything to bring joy to Corinthians fans!"
Willian played for Corinthians' youth teams between 1998 and 2006 before stepping up to the senior side in 2006-07 prior to his switch to Ukrainian powerhouse Shakhtar Donetsk 14 years ago.
Before leaving for Europe in 2007, Willian scored two goals in 41 appearances across all competitions for Corinthians.
At Arsenal, Willian made 37 appearances in all competitions during the 2020-21 season, scoring just the one goal from 27 shots.
He did set up seven goals for team-mates, easily outperforming his expected assists total of 3.14, with two of them coming from dead-ball situations.
However, Willian only made four Premier League starts after the turn of the year as Mikel Arteta went with alternative options in his team.
"I want to thank you for the effort, board, technical committee," Willian said. "I respect this crowd a lot, the affection they have for me. I am back!"
Willian leaves an Arsenal side struggling amid mounting pressure on manager Arteta.
Arsenal are winless and goalless after three Premier League games for the first time ever, Manchester City crushing the Gunners 5-0 on Saturday.
That loss extended the Gunners' top-flight losing run to nine against City, their outright longest-ever run of consecutive defeats against an opponent in their league history.
Indeed, Arsenal are just the second team after Wolves in 2003-04 to lose their first three games and have a goal difference of minus-nine – a season in which Wolves finished bottom of the table.