The 31-year-old signed a three-and-a-half-year-deal with the French club. It is hoped he will play a key role in helping the 2017 Ligue 1 champions avoid relegation.
He will reunite with former Arsenal team-mate and close friend Thierry Henry at Stade Louis II, with the Gunners’ all-time top goalscorer taking his first steps in management after Leonardo Jardim was sacked in October.
“It is a great pleasure to join AS Monaco, a new project for me,” Fabregas said in a statement.
“The group is quality with young players and a young coach. I’m here to help the team.
“I’m looking forward to starting, we have a great match to play in Marseille on Sunday. I am very excited.”
Fabregas’s departure from Chelsea sees him end four-and-a-half years at Stamford Bridge after he joined the Blues from Barcelona in 2014.
The Spain international helped the west London outfit win two Premier League titles, the FA Cup and the League Cup in a little above four years.
