Luiz has signed a two-year deal at the Emirates.
After six years (over two spells) with Chelsea, David Luiz is now a Gunner.
Arsenal signed the Brazil international for £8m before the transfer window shut down.
The Brazilian, who made 248 appearances for the Blues across two spells, refused to train with Frank Lampard’s side on Thursday and has surprisingly forced through a shock move to the Emirates, putting pen to paper on a two-year deal at the north London club.
And Gunners boss Unai Emery, who worked with Luiz at Ligue 1 side Paris Saint-Germain, told the club’s official website: "David has huge experience and I look forward to working with him again. He is a well known player and adds to our defensive strength."
Luiz won 4 major trophies with Chelsea – 2 Europa League, the 2012 Champions League and 2016-17 Premier League.
He is the only player in Chelsea history to have played in 3 European trophy final wins (Gary Cahill also has 3 medals, but the Englishman only played in 2 finals).