Leonardo Jardim has been announced as Monaco's new coach, replacing Claudio Ranieri.
The former Sporting Lisbon coach has signed a two-year deal with the principality club, with the option for a further year, and will officially take charge when the club begin pre-season training on June 30.
Jardim, 39, told the club's official website: "I am very happy to work for Monaco as it is a big club. I fully believe in this project and I think that this group can go far.
"AS Monaco is a team with players full of quality. There are many young players with a lot of talent. I am going to do everything to help them progress."
The Venezuela-born Portuguese coach added: "The first thing is to start learning to speak French. I have been taking lessons for a few days now, it is question of respect towards the supporters and the people of Ligue 1."
Jardim started his coaching career as assistant at Madeira-based side Camacha in the Portuguese third division, stepping up to head coach in 2003.
He led Chaves into the second tier and achieved promotion to the top flight with Beira-Mar in 2010, only to resign midway through the following season.
He secured third place in his one season in charge of Braga before leaving amid reports of a clash with club president Antonio Salvador, and was sacked by Olympiacos while 10 points clear atop the Greek Superleague.
He led a youthful Sporting side to second place last season, achieving their first Champions League qualification in five years and improving on their 2012-13 points tally by 25 points in the process.
Monaco vice-president Vadim Vasilyev said: "He is a manager who has obtained excellent results with all of his previous clubs.
"He has a strong motivation and is part of a new generation of managers with new dynamics. He is ambitious, just like us. This is exactly the type of profile that we have established.
"We were instantly convinced that Leonardo Jardim was the man to take our project forward. We are delighted to be working with him."
Ranieri led Monaco to second place in Ligue 1, behind fellow big-spenders Paris St Germain, having steered them to promotion the previous season.