The Portuguese's tenure at Old Trafford had been pretty dreadful for the last few months and fans were getting tired of seeing limp and lifeless performances from their side, with star players performing well below their usual standards.
After a comprehensive 3-1 loss to the close rivals Liverpool on Sunday, the Man United board decided to cut their losses and bid Mourinho farewell in a bid to try and repair their domestic and European campaign.
Speculation immediately began to resonate about who would replace him and few a few hours Twitter was awash with jokes and memes at Mourinho's expense. Some of them were good. Some of them were bad.
So, whilst you're still processing the news about a man losing his job and somehow still earning £24 million, allow us to distract you with 20 of the best and worst reactions from the Twitter on today's biggest news story.
1. Pizza Hut's take wasn't the best.
Hi @ManUtd, we've received a CV from Mr J Mourinho.
He's just applied for a job as pizza chef.
Please can you send… https://t.co/9y6cQExKQA
— Pizza Hut Restaurants (@Pizza Hut Restaurants)
2. David Lammy's casual trolling of Mourinho and Theresa May was perfect.
An arrogant manager with a team full of overly-paid right-wingers has finally lost the confidence of their team. Th… https://t.co/D45MR8e0v3