French data regulators have fined Google 50 million euros, or 57 million dollars, for breaching EU online privacy rules.
It is the biggest such penalty levied against a U.S. tech giant.
French regulators said Google failed to provide enough information to users about its data consent policies and didn't give them enough control over how their information is used.
In a statement, Google said it was studying the decision to determine its next steps, adding it is committed to meeting high standards of transparency and control.
Privacy groups first filed complaints against the firm in May last year, when the EU's new General Data Protection Regulation took effect.
The GDPR allows users to better control their personal data and gives regulators the power to impose fines of up to four percent of global revenue for violations.