This chapter defines decolonisation and outlines briefly the geographical and historical processes by which it takes place. It examines the processes by which decolonisation happens through formal education and digital technology. The chapter makes the distinction between educational technology or EdTech and the wider and informal use of any digital technologies outside education systems. It outlines the ways in which colonialism is present in both generalist hardware, software, systems, and infrastructure and in dedicated educational technologies, in the pedagogies embedded and embodied in these technologies, and the ways in which these technologies are developed, procured, and deployed. The chapter provides an initial outline of these challenges intended to stimulate discussion and research. It also provides some preliminary guidance on how the various stakeholders in the educational use of digital technology, in their widest senses, can start to address the issues in their own roles and practice. The conclusion is that colonisation, in some form or other, is present in all educational technology but that responses and recommendations at every level are possible and worthwhile.