1220 GMT October 20, 2019
"I'm pleased to be making this long-term commitment to AS Monaco," the former Sporting Lisbon and Braga manager said on the principality club's website.
"This contract extension is a mark of confidence from the club and the directors. We have worked hard this season to put in place this new project, and I'm convinced that the best is still to come, Reuters reported.
"There are lots of quality youngsters in this team. We need to continue with what we've shown this season. The club is ambitious and so am I," added Jardim, who replaced Claudio Ranieri when the Italian left for a short reign as Greece coach.
The 40-year-old Jardim, who took over last June on a two-year contract after joining from Sporting, has led Monaco to the verge of a Champions League spot for next season.
They are third in the table with 65 points, two ahead of Olympique Marseille and St. Etienne, with two games left. If they finish third they will go into the third qualifying round.
Monaco also reached this season's Champions League quarter-finals where they lost 1-0 to Juventus on aggregate having upset Arsenal in the last 16.
"This is an important step for our club, as we are keen to build for the future with Leonardo Jardim," said Monaco vice-president Vadim Vasilyev.
"With his backroom staff, he has done a remarkable job this season, getting very good results in Ligue 1 and the Champions League.
"We are confident that Leonardo is the right coach for our philosophy, to enable the club to be a major player on the national and international scene, while allowing our talented young players to develop."