The shock announcement that Conte was leaving the Serie A club came in a video posted on the club's official website - just a day after the start of pre-season training.
The 44-year-old steered Juventus to a third consecutive title last season, the first time the club has achieved the feat since a five-season title run in the 1930s.
But after the celebrations had subsided, he hinted he could quit the Turin club if they failed to invest in players during the summer break, ahead of a fresh assault on the UEFA Champions League.
Speaking to the club's website on Tuesday, Conte said: "I have decided to terminate my contract with Juventus.
"I have matured with time and my feelings led me to make this choice. It may be more difficult to keep winning with Juventus.
"An enormous thank you for what you have given to me as a player and as a coach. I have always been close to you. I want to say that the journey taken in recent years has been historic."
Juve chairman Andrea Agnelli wrote on the club's website: "Dear Antonio, you have been a great leader and this news saddens me greatly.
"Three years together have led us to write history with three consecutive titles and two Italian cups.
"You have given a group of highly talented professionals who will be at the disposal of the new coach to continue writing the future.
"You are in the history of the Bianconeri colours and whatever choice you make, a Juventus victory will always make you smile. Antonio, thank you for everything. Til the end."
Conte was linked with Monaco last season and there has already been speculation that he could now be poised to take over from Cesare Prandelli as Italy coach.
Prandelli quit the role last month following Italy's exit at the group stage of the World Cup in Brazil.