The Commission nationale de l'informatique et des libertés (CNIL) has imposed two penalties on Google that amount to €100 million (£90m), and one on Amazon for €35 million (£32m).
Both firms were also given a three-month ultimatum to make changes to the way they notify users about cookies or face additional daily fines of €100,000-plus.
According to CNIL's investigations, Google didn't provide enough information to users in France about why and how cookies are used and Amazon was fined for placing cookies on people's computers without their consent.
"On 16 March 2020, the CNIL conducted an online investigation on the website google.fr and found that when a user visited this website, cookies were automatically placed on his or her computer, without any action required on his or her part," the regulator said. "Several of these cookies were used for advertising purposes."
In a statement, Google said it stood by its record of providing upfront information, clear controls, strong internal data governance, secure infrastructure and helpful products.
"Today's decision under French ePrivacy laws overlooks these efforts and doesn't account for the fact that French rules and regulatory guidance are uncertain and constantly evolving," a Google spokesperson said. "We will continue to engage with the CNIL as we make ongoing improvements to better understand its concerns."
"We continuously update our privacy practices to ensure that we meet the evolving needs and expectations of customers and regulators and fully comply with all applicable laws in every country in which we operate," an Amazon spokesperson said in a statement.
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Bobby Hellard is ITPro's Reviews Editor and has worked on CloudPro and ChannelPro since 2018. In his time at ITPro, Bobby has covered stories for all the major technology companies, such as Apple, Microsoft, Amazon and Facebook, and regularly attends industry-leading events such as AWS Re:Invent and Google Cloud Next.
Bobby mainly covers hardware reviews, but you will also recognise him as the face of many of our video reviews of laptops and smartphones.