An investigation by the regulator found that the adverts were “intended to influence public opinion” on “matters of public controversy”.
Such advertising is not allowed on TV according to UK law.
A total of 56 adverts promoting Saudi Arabia were broadcast on Sky 1 on March 7 2018.
This coincided with a controversial visit to the UK by Saudi Crown Prince Mohammed bin Salman.
The minute long advert showed clips of women driving and cinemas opening, in a clear effort to show that Saudi Arabia is modernising.
A voiceover claimed “things are undoubtedly changing” in Saudi and argued the UK’s friendship with the Kingdom “brings increased prosperity and security for both countries”.
The commercials were paid for by the Saudi Centre for International Communication, a branch of Saudi Arabia’s Ministry for Culture and Information.
The Ofcom ruling overturns the original decision from Clearest, which screens adverts in the UK and approved the Saudi one for broadcast.
Clearest unsuccessfully attempted to defend its position by arguing the adverts promoted UK-Saudi trade.
Sky 1, the broadcaster who showed the adverts, are not facing any punishment.
However the ruling will make it very difficult for Saudi Arabia to place any adverts on UK TV in the future.
In addition to the TV adverts the visit of Crown Prince Salman saw large paid for posters across London celebrating the event.
The Saudi Government also paid for advertising in UK newspapers, including The Guardian.
This is perfectly legal, as it wasn’t broadcast on TV, and The Guardian insists it had no impact on their editorial policy.
Due to its human rights record and involvement in the ongoing civil war in Yemen the UK’s close relationship with Saudi Arabia has been controversial.