This report highlights a complex situation in which some forms of data localisation are seen as useful and largely uncontroversial, while others as a significant barrier to the digital economy. Contributing to the review of the implementation of the OECD Privacy Guidelines, the report emphasises the need to recognise the effect that data localisation can have on transborder data flows, but suggests that the conditions that data privacy laws traditionally impose do not necessarily amount to data localisation measures. Focusing on data localisation in the context of data privacy and the governance of globalised data flows, the report proposes a definition for data localisation, outlines a roadmap to ensure that data localisation does not impede transborder data flows, and makes recommendations to support such work. In particular, it emphasises the relevance of the accountability principle and the proportionality test articulated in the OECD Privacy Guidelines in evaluating data localisation measures.