The 52-year-old Portuguese returned to Chelsea in 2013 for his second stint in charge and ended the team’s five-year Premier League title drought in May.
“If the club is happy, I am happy,” Mourinho said. “It is important we have this continuity and I hope we can enjoy more success in the future — for the fans, the players and the club.
“I said when I returned here two years ago that I have a special feeling for this club and nothing changed. It is the club closest to my heart and I am very happy to know I will be staying here for a long time.”
The new season begins on Saturday against Swansea, with Mourinho looking to win back-to-back titles as he achieved in 2005 and 2006.
“We are very happy that Jose has committed four more years to the club,” director Marina Granovskaia said. “Since his arrival two years ago he has carefully developed the playing squad and brought trophies to Stamford Bridge.
“We look forward to the next four years and the continued success of the team.”
“The real football starts tomorrow,” he said. “None of the big leagues in Europe have started yet. Not Spain, Italy, Germany, Portugal. Everybody is waiting for tomorrow, so finally people have proper football – some people watching in the stadiums, some at home on TV. Let’s try and be a good team this season and try to be here in March, April and speaking about winning something.”
Yahoo contributed to this article