Willoughby and Philip Schofied were interviewing Episode 8 star John Boyega when the massive slip-up happened.
The Last Jedi is out in cinemas on December 14 and fans have waited two years to find out what happens after the thrilling events of The Force Awakens.
Although tHe internet is awash with theories and reported leaks, most of the plot in under wraps and the filmmakers have promised huge shocks, twists and surprises.
Did the UK breakfast show just give away one of the biggest of all?
WARNING: SPOILERS
Boyega was being interview over a live link from his hotel.
During the friendly chat, Holly excitedly said: “Fans will be happy Yoda is back!”
There was a shocked silence as the gobsmacked actor clearly tried to figure out what to do or say.
The British star, who plays renegade First Order deserter Finn, looked stunned and said: “Oh, Holly. Holly. Holly. You can’t tell the fans exactly what happens!”
Willoughby actually tried to cover her tracks by claiming that the information was already common knowledge and had already been revealed “out there.”
Fan fury immediately erupted online, with many comments not just blasting the potential spoiler but also the presenter’s apparent unapologetic stance.
As the gaffe happened live, comments already began to spread online with one saying: “Did Holly Willoughby just spoil Star Wars for everyone?”
Boyega, meanwhile, also made his concern clear and added: “Gosh! Things happen, get your ticket. Man, I can’t reveal that.”
Schofield clearly realised a massive mistake had been made and joked: “Maybe Yoda isn’t back? Maybe it was just a short alien.”
Boyega gratefully seized the reprieve and played along: “Maybe it was me on my knees.”
STAR WARS THE LAST JEDI IS OUT ON DECEMBER 14