Tuchel, 49, took charge at Stamford Bridge in January 2021, signing an 18-month contract. The former Borussia Dortmund and Paris Saint-Germain manager won the UEFA Champions League in his first season. He replaced club legend, Frank Lampard at the helm.
But the decision to sack the German by the club's new owners came a day after Chelsea lost to Dinamo Zagreb 1-0 in their Champions League 2022-23 campaign opener.
Chelsea Football Club part company with Thomas Tuchel.— Chelsea FC (@ChelseaFC) September 7, 2022
On the domestic front, the Blues have lost two of their first six games in the English Premier League games.
Chelsea were the highest-spending team in Europe during the transfer window, spending nearly USD 300 million.
Raheem Sterling, Kalidou Koulibaly, Marc Cucurella, Wesley Fofana and Pierre-Emerick Aubameyang came in for big fees during the window.
Chelsea said that the owners believe it is "the right time" to bring in a new head coach is a statement.
"As the new ownership group reaches 100 days since taking over the Club, and as it continues its hard work to take the club forward, the new owners believe it is the right time to make this transition," the statement read.
"On behalf of everyone at Chelsea FC, the club would like to place on record its gratitude to Thomas and his staff for all their efforts during their time with the club. Thomas will rightly have a place in Chelsea's history after winning the Champions League, the Super Cup and Club World Cup in his time here."
Owner Todd Boehly has reportedly placed Tuchel's coaching staff in temporary charge.
Tuchel went on to win the UEFA Super Cup and FIFA Club World Cup in his first season.
Tuchel's Chelsea reign also witnessed a tumultuous period where the club changed ownership after Roman Abramovich was forced to put the six-time English champions after being sanctioned by the British government in the wake of Russia's invasion of Ukraine.
It was followed by a USD 3.1 billion takever by a consortium led by by Boehly.