Conte had been expected to go at the end of last season after Chelsea, who won the 2016-17 Premier League title in his stellar first campaign in charge, finished fifth and failed to qualify for the Champions League.
Conte, 48, had returned to full pre-season training at the start of the week despite huge uncertainty surrounding his future at the club, but with one year left on his contract the Blues have chose to relieve the Italian tactician from his duties in west London.
While the bitter battle between Chelsea and Conte rages on in the background, the club will officially confirm Sarri as the new head coach with Blues legend Gianfranco Zola joining his backroom team.
Chelsea began a terse, four-sentence statement on its website, "Chelsea Football Club and Antonio Conte have parted company". "In the title winning season, the club set a then-record 30 wins in a 38-game season".
'We wish Antonio every success in his future career'.
Conte also fell out with David Luiz and Willian, and used press conferences last season to accuse the board of not signing his targets.
Assuming both deals get over the line, Jorginho and Sarri should be at Chelsea by this weekend at a total cost of around €65m to secure both signings.
Napoli recently replaced Sarri with former Chelsea manager Carlo Ancelotti but the 59-year-old remains under contract at the Serie A club.
Chelsea legend Gianfranco Zola and Giovanni Martusciello are expected to join Sarri's backroom staff while Italian-Brazilian midfielder, Jorginho, is now undergoing a medical at Cobham and will also follow Sarri from Naples to London.