Jorginho joined Arsenal from Chelsea in a shock deadline-day move after the Gunners cooled their interest in Brighton midfielder Moises Caicedo.
The 31-year-old Italian does not fit Arsenal’s transfer strategy over the past few years, which has focused on younger players.
But manager Mikel Arteta believes Jorginho will bring “leadership skills” that could be crucial as Arsenal bid to stay clear of Manchester City at the top of the Premier League.
Sporting Director Edu said: “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.”
Arsenal have been desperate to sign a midfielder this month to strengthen their title bid.
Mohamed Elneny is out with a knee injury and Arteta wanted to strengthen that area.
Arteta said: “Jorginho is a midfield player with intelligence, deep leadership skills and a huge amount of Premier League and international experience.
“Jorginho has won in his career, but he still has the hunger and huge willingness to contribute here.
