In its 2018 report on the state of EU-Russia political relations, the European Parliament condemned Russia for its use of disinformation campaigns, referring specifically to Russia's use of social media to interfere in the affairs of EU member states (European Parliament 2018). As a space, therefore, in which existing tensions in the EU-Russia relationship are played out, attention to social media is warranted. However, as 'Internet-based applications' (Kaplan in van Dijck and Poell 2013), social media are caught up in arguments about the future of internet governance generally, such that, when it comes to social media, EU-Russia relations exist within a wider context. Each actor is just two among an array of actors facing similar challenges as technology develops in such a way and at such a pace as to outstrip the capacity of any governmental actor to anticipate or control fully developments in the information space. The EU and Russia have responded in ways that are not necessarily bound up in their mutual relations. Their separate responses nevertheless illuminate the relationship, particularly with respect to their political and normative differences and how they act on behalf of their societies in terms of reinforcing democracy or undermining it.'[D]esigned to facilitate social interaction and for using, developing and diffusing information through society' (Kavanaugh et al. 2012: 482), social media are spaces in which a range of actors, including governmental, can insert themselves in both transparent and opaque ways. This explains the resurgence of political, scholarly and journalistic work on propaganda, misand disinformation (Bennet and Livingstone 2018;Helmus et al. 2018;McGeehan 2018;Nimmo 2016). This agenda is driven by the actions of Russia, the dogwhistle tactics of certain EU leaders and politicians (witness the conspiratorial discourse of Italy's Matteo Salvini on the 'genocide of the Italian people' or Hungary's Orban on 'Islamic expansion') and by the Trump administration and associated claims of 'fake news'.This chapter proceeds as follows. It first considers the literature regarding what social media are, talking through the platforms and their 'ecological' environment, the context in which they and their users operate. This first section also examines the evolution of social media research, from earlier preoccupations with identifying users 1 to more recent research concerned with patterns of and motivations for usage, as well as the response of governments to developments here. The chapter then moves to a discussion of Russian attempts to manipulate EU societies using social (and other) media before looking at the separate responses in Russia and in the EU