Yes, this is explicitly prohibited. Article 11 of the Saudi E-Commerce Law states that electronic advertisements must not contain any false display, statement, allegation, or misrepresentation that could — directly or indirectly — deceive or mislead the consumer. Fake reviews, inflated ratings, and misleading promotional claims all fall within the scope of this prohibition.
Article 10 reinforces this by treating electronic advertisements as binding contractual documents. This is significant: if a seller advertises a product with specific features or at a specific price, those claims become part of the contract. If the delivered product does not match the advertised description, you have grounds to seek a remedy, including returning the item.
Under Article 12, if a seller is found to have violated the advertising rules in Article 10, they face consequences in addition to the general penalties in Article 18 (which range from a formal warning up to fines). Practically, if you believe you were deceived by a misleading Saudi online ad, document everything — screenshots, product descriptions, and your order confirmation — before reporting to the Ministry of Commerce.
This is general legal information, not legal advice. For advice on your specific situation, consult a lawyer licensed in Saudi Arabia.