The fine is at a record level and exceeds the previous record sum of 746 million euros previously awarded to online giant Amazon.
Meta will now have five months to end all transfers of personal data to the US and six months of respite regarding, among other things, the storage in the US of data originally from the EU.
Meta said it considered the decision "unfair" and that the company intends to appeal the decision as it risks "dividing the internet into national and regional departments".
It's not the first time Meta has been fined. In 2022, the company was fined nearly £2.9 billion by the Irish Data Protection Authority. That's after data from over half a million users was leaked on a computer hacker's website.