Arsenal have confirmed the signing of Jorginho on an 18-month deal from London rivals Chelsea.
The 31-year-old arrives at the Emirates Stadium in a deal thought to be worth around £12m, putting pen to paper on a contract that will keep him in North London until the summer of 2024.
Jorginho will wear the number 20 shirt for Arsenal, and could make his debut in Saturday's Premier League clash with Everton at Goodison Park.
"Jorginho is a midfield player with intelligence, deep leadership skills and a huge amount of Premier League and international experience," manager Mikel Arteta told the club's official website.
"Jorginho has won in his career, but he still has the hunger and huge willingness to contribute here.
"We are so pleased to sign Jorginho and welcome him and his family to the club."
Arsenal sporting director Edu added: "Jorginho is an established professional with a strong mentality who brings quality and experience into our squad.
"He is a player who fits our style of play, and he joins us at a very good moment where he can contribute in a key position to help maintain our momentum. We welcome Jorginho to Arsenal."
The Premier League leaders have been in the market for a midfielder this month, but were frustrated in their big-money pursuit of Moises Caicedo by Brighton & Hove Albion's refusal to sell.
The Gunners are understood to have seen bids of £60m and £70m for the Ecuadorian rejected, despite the midfielder's public request to be allowed to speak to the club.
Arsenal's need to bolster their ranks was increased earlier on deadline day with the news that Mohamed Elneny is set for a lengthy spell on the sidelines through injury.
Jorginho joins Arsenal after four-and-a-half years at Chelsea, during which time he made 213 appearances for the club, scoring 29 goals.
The Brazil-born Italy international helped the Blues to Champions League and Europa League glory during his stay at Stamford Bridge, while he also helped Italy to the Euro 2020 title with victory over England in the final at Wembley.
Jorginho, who previously played for Napoli before moving to Chelsea, finished third in the voting for the 2021 Ballon d'Or and had been heavily linked with a move to Manchester City during Arteta's time as an assistant coach there.
Chelsea, meanwhile, are attempting to complete a British-record deal to sign Enzo Fernandez before the 11pm deadline tonight.