In 2018, the Californian government adopted a new data protection framework. The flagship of this framework is the California Consumer Privacy Act (CCPA). As this new framework is widely considered to resemble the European Union’s (EU’s) General Data Protection Regulation (GDPR), this article intends to investigate whether the Brussels Effect could explain this resemblance. We apply process-tracing to test if the Brussels Effect causally connects the GDPR with the CCPA. The analysis is based on a careful evaluation of three sets of evidence. Firstly, privacy policies of Apple, Facebook, and Google are examined. Secondly, lobbying concerning the alignment of the implementation of the CCPA with the GDPR is scrutinized. Lastly, it is investigated whether the Californian government has used arguments linked to the Brussels Effect while drafting the CCPA and its subsequent implementing regulations. It is concluded that the Brussels Effect has indeed played a role in the adoption of the CCPA. Nevertheless, it has become clear that the impact of the Effect varies depending on exactly which provision of the GDPR is examined.