Conte spent two seasons in charge of the Premier League club, leading them to the title in his first year.
The London club says, "We wish Antonio every success in his future career".
Former Napoli boss Maurizio Sarri is in line to take over in west London in time for the new season which begins on 10 August, but the manner in which Conte has been dismissed is another chapter in the tale of Chelsea's mistreatment of managers.
The Blues were unable to defend their title, finishing fifth last season and missing out on Champions League.
In the wake of Chelsea's FA Cup win, Willian obscured Conte in a team celebration photograph posted on Instagram.
Antonio Conte's dismissal at Chelsea surprised nobody.
Sarri spent three years at the club and led it to two runner-up finishes and a third place, playing an entertaining and high-energy brand of football like that seen at Man City under Pep Guardiola, Tottenham under Mauricio Pochettino, and Liverpool under Juergen Klopp.
The chain smoking former Empoli manager - who will have to restrain himself on the touchline in England where smoking is banned - was named Serie A Coach of the Year in 2016-17.
The Italian has taken most of his backroom staff with him with only Paolo Bertelli, Carlo Cudicini and goalkeeping coach, Gianluca Spinelli, considering staying at Chelsea for the coming season.
They reportedly include Brazil-born Italy global midfielder Jorginho from Napoli, CSKA Moscow´s Russian playmaker Aleksandr Golovin and Italian defender Daniele Rugani from Juventus, the side that edged Napoli in the Serie A title race.