After taking charge in December 2023, the Portuguese head coach helped the Reds maintain their top-flight status, guided them to their highest finish since 1994-95, and brought European football to the City Ground for the first time in three decades.
The 51-year-old's position had been uncertain for two weeks, though, after he admitted his relationship with owner Evangelos Marinakis had deteriorated.
The appointment of Nuno's replacement is imminent, with former Tottenham boss Ange Postecoglou one of the names in the frame.
What do you make of the decision to sack Nuno? Was it the right time to make a change or do things seem a little rash?
Nuno leaves Forest 'beloved by fans'published at 06:36 BST 9 September
06:36 BST 9 September
Nick Mashiter Football reporter
Image source, Getty Images
In just under two years, Nuno Espirito Santo guided Nottingham Forest from a relegation battle back into Europe for the first time in 30 years.
He leaves beloved by Forest fans but after a clear breakdown in relationship with owner Evangelos Marinakis.
He created a siege mentality which served Forest well and, despite both being big characters, it appeared a perfect match between him and Marinakis.
Last season's shock European challenge ended in missing out on Champions League football on the final day, a finish which may now have been crucial to Nuno's future.
Forest still finished seventh and reached the Europa League - being promoted to the competition after Crystal Palace's demotion - but for Nuno, the club did not prepare quickly enough this summer.
Successive swipes in news conferences about the club's slow movement in the summer transfer market included the revelation that his relationship with Marinakis had changed.
It was a shock, given how guarded the Portuguese manager usually is.
Forest spent more than £180m this summer, but Nuno was unhappy with being unable to integrate his new players swiftly enough.
Suggestions of a rift with Edu, Nottingham Forest's global sporting director, lingered and the 3-0 defeat by West Ham last week was the worst performance of his reign, coming before talks with Marinakis about the club's future direction following his comments.
Nuno said, although not entirely convincingly, that he expected to be in charge for Saturday's trip to Arsenal - but Forest's future is now without him.
A search for his replacement is not expected to be a lengthy one, with former Tottenham boss Ange Postecoglou previously linked.
Internal tensions with Marinakis force Nuno outpublished at 06:24 BST 9 September
06:24 BST 9 September
Sami Mokbel Senior football correspondent
Image source, Getty Images
Despite Nottingham Forest's success on the pitch during Nuno Espirito Santo's time as manager, his relationship with owner Evangelos Marinakis became increasingly strained.
In August, Nuno revealed he feared for his job.
Internal tensions at the club were believed to be centred around disagreements over their transfer business. Nuno had previously criticised the club's activity in the summer transfer window, saying they had wasted a good chance.
"I always had a very good relationship with the owner - last season we were very close and spoke on a daily basis. This season it is not so well," Nuno said in a news conference (watch that clip below).
"Our relationship has changed and we are not as close. Everybody at the club should be together, but this is not the reality."
In total, Nottingham Forest made 13 summer signings for about £196m, based on reported initial fees.
As for their outgoings, Anthony Elanga, Danilo and Wayne Hennessey were among the players whose Forest careers ended this window.
Forest later said the incident was because of the owner's frustration that striker Taiwo Awoniyi had continued to play following an 88th-minute injury, which subsequently required what was described as "urgent" surgery.
The club said there was "no confrontation" and it was "fake news" to suggest otherwise.
However, those missed points against an already-relegated side were part of a run that saw Forest - who had been in contention for Champions League qualification - only pick up eight points from their last eight matches of the 2024-25 campaign.
Image source, Getty Images
