Conte, 48, was widely expected to lose his job at the end of last season, with the Blues finishing in fifth position in the Premier League table.
The Italian was surprisingly still in charge of the English club when they resumed pre-season training earlier this week, but according to Sky Sport Italia, he has now been relieved of his duties.
Conte's contract with Chelsea was due to expire in 2019, meaning that the Italian will be due a pay-off by owner Roman Abramovich.
The former Juventus manager led Chelsea to the Premier League title in his first year in charge, before landing the FA Cup last term with a 1-0 win over Manchester United.
The Blues will begin their pre-season with a clash against Perth Glory on July 23.