Speculation had been rife over the 35-year-old's future with his contract running down in west London, and the former West Ham midfielder confirmed in a statement on Monday evening that he has played his last game for the Blues.
Lampard has been heavily linked with a move to the United States to join New York City FC in recent days, but his statement gave no indication over where his future now lies.
"When I arrived at this fantastic club 13 years ago I would never have believed that I would be fortunate enough to play so many games and enjoy sharing in so much success," he said.
"This club has become part of my life and I have so many people to thank for the opportunity
Firstly, Ken Bates, who put his neck on the line to sign me as a young player and without him I would not have even begun this experience.
"Roman Abramovich, the man who saved our club and took us all to new levels
His desire to push the club to the top of the football world has rubbed off on everyone.
"All the managers and coaches who have helped me develop my game during the time I have been here
I have learnt from every one of them.
"All the brilliant team-mates who I have been lucky enough to train and play alongside for so long
Not just their football qualities but also the friendships I have gained along the way.
"I'd also like to give a special mention to all the staff and people behind the scenes at the club who do not receive the glory but without them the club would simply not function.
"The club will move forward, and as a Chelsea man I have no doubt that with the quality of the players that are there, they will continue with the success that we have all enjoyed over the past seasons."
Source : PA
Source: PA