The 32-year-old's loan spell at Reading finished earlier in May he has now officially announced his departure from Stamford Bridge.
He made just 23 appearances for the club, netting on one occasion during his ill-fated five-year spell.
His last appearance in a Chelsea shirt was the 2018 Community Shield final, and Drinkwater described his time with the Blues as 'a business deal gone wrong.'
The Manchester-born midfielder cited injury and bad behaviour, which includes a drink-driving ban and a nightclub fight, as some of the reasons he failed to hit the ground running with the west London club.
After becoming surplus to requirements, he was eventually loaned out to Burnley, Aston Villa, Reading and Turkish side Kasimpasa.
In a frank Instagram post, Drinkwater wrote: "My time at Chelsea has come to an end… actually feels really strange writing this. Me, the club and fans are hugely disappointed with the outcome, there is no doubt about that.
"Injuries, how I have been treated, mistakes I have made, issues off the pitch, lack of game time… the list of excuses could be endless but I would not and cannot change what's happened.
"I'm going to look at positives over the past five years. I have played with great players, coached by awesome managers, worked with some brilliant staff, met some fantastic people, lived in some beautiful places, travelled the world and won some more silverware.
"Football's a fantastic sport but this for both parties was a business move gone wrong, it's as black and white as that.
"To the Chelsea fans I apologise for how this has turned out I would of loved for u to see me at my best in that shirt doing what I love. All the best x."
Chelsea full-back Marcos Alonso said in reply to the post: "All the best bro! Top player and top man!"
Other teammates including Antonio Rudiger, who's expected to join Real Madrid in the summer as well as Mason Mount and Billy Gilmour also sent their wishes to Drinkwater.
During his time at Stamford Bridge, Drinkwater got his hands on the FA Cup in the 2017/18 season where he played 22 times under former Chelsea boss and current Spurs manager Antonio Conte.
Drinkwater linked up with Thomas Tuchel's side last summer for pre-season training, later joining Reading and spending the campaign with the Royals where he made 24 appearances.
He is now a free agent and searching for a new club as he looks to resurrect his career.