“Social media has changed the face of politics in Nigeria.” So said many political candidates, professionals, non-governmental organisation (NGO) and civil society actors, scholars and political advisers interviewed as part of this research project in the lead-up to, and the aftermath of, the 2019 presidential and gubernatorial elections. To what extent, though, is this true? Moreover, if it is true, how exactly has it changed politics – and with what effects on political discourse, information flows, campaign strategy, the democratic process and, indeed, election results themselves? This research – funded by WhatsApp – helps to provide some answers to these questions by focusing specifically on the role of WhatsApp in Nigerian electoral politics. Although the centrality of social media platforms to information flows around electoral processes globally is now widely acknowledged by scholars, practitioners, industry, commentators and even politicians themselves, WhatsApp’s influence has received far less attention in this regard than Twitter or Facebook. WhatsApp, a Facebook-owned private messenger application, is nonetheless playing an equally important, though harder to quantify role, in the spread of information during election campaigns and votes. Ahead of national elections in April and May 2019, for example, India’s political parties were pouring money into creating hundreds of thousands of WhatsApp group chats to spread political messages and memes.