On 15-16 February 2018 the Organisation for Economic Co-operation and Development (OECD) hosted a Workshop on Digital Security and Resilience in Critical Infrastructure and Essential Services. The workshop brought together over 120 participants to discuss the effects of growing digital transformation on the resilience of critical infrastructures and essential services which rely increasingly on cross-border digital infrastructure. Over 25 experts discussed digital security in the financial, energy and transport sectors, in relation to the delivery of public sector services, and from the digital security public policy making perspective. Issues faced by SMEs were also addressed throughout the event. This report provides key cross-cutting high-level policy messages from the workshop, an issues paper developed to prepare the event, as well as a detailed account of discussions in each session.