This Practice Note examines how to determine which system of law is applicable to a contract of employment or employment relationship. It provides an overview of the Rome Convention and Rome I, which are now assimilated EU law. It then examines the key employment-specific provisions in Rome I, now Assimilated Rome I, how to determine which law applies, the ‘habitual place of work’ test, the ‘closer connection’ test, non-derogable provisions, overriding mandatory provisions, public policy issues and who should apply the applicable law. It also provides an overview of Rome II, now Assimilated Rome II, and its application in the employment context.