This chapter examines the role of civil society activities in promoting accountability in respect of the Internet Corporation for Assigned Names and Numbers (ICANN), one of the principal regulatory instruments for global cyberspace. The chapter first briefly reviews the general history and organisation of ICANN as a multistakeholder form of global governance. A second section then reviews civil society engagement of the institution: the kinds of citizen groups that have interacted with ICANN and the ways that they have done so. Particularly significant in this regard is the formal participation of civil society actors on the board and committees of ICANN. The third part of the chapter proceeds to assess the accountability impacts of this civil society involvement, in terms of enhancing (albeit sometimes to only limited degrees) processes of transparency, consultation, evaluation and redress in ICANN.