Contesting hate draws on a unique five-year dataset, which includes social media data, interviews with digital activists and mainstream media analysis, generated by the project '#ContestingIslamophobia: Representation and Appropriation in Mediated Activism'. This book provides an in-depth analysis of how social media have been used to contest the circulation of racialised Islamophobia, in relation to a range of events wherein Islamophobic narratives have been yoked to white supremacism, Hindu nationalism and polarising 'culture wars' debates. Focusing on archetypal 'trigger events' that have resulted in the intensification of Islamophobic discourse - the Christchurch white supremacist terrorist attacks, Brexit and the Covid-19 pandemic - we identify key actors and networks involved in these narratives, and foreground successful (and less successful) counter-narrative tactics for contesting hate. In the process, we set out a new theoretical and methodological framework for conceptualising and researching digital discrimination and activism.