Radical right organisations like many other extremist communities have an increasingly prominent and active online presence, to the extent that some communities may have a more active online presence than offline (Bartlett and Littler, Inside the EDL: Populist Politics in a Digital Age. London: Demos, 2011; Morrow and Meadowcroft, Political Studies, 2018). This digital space is arguably both an extension of the offline and a unique space in its own right, and these digital spaces can function for the radical right as a platform for communication, recruitment and as an echo chamber with the potential to increase polarisation of views (Awan, Society, 54(2), 138–149, 2017). Research focusing on the online spaces and the use of them by the radical right has the potential to offer great insight but raises challenges in relation to the practical issues of collecting data, the analysis and importantly unique ethical issues. In this chapter we consider first how traditional quantitative and qualitative measures can be applied and extended to the online, and used to access hard-to-reach participants and communities. We then consider unique approaches to online research in reference to radical right organisations such as Big Data methods and the use of Corpus Linguistics, Corpus Assisted Discourse Analysis and Sentiment Analysis. These approaches can utilise the vast volume of online data available from such spaces and communities in ways that traditional methods cannot. Such online research raises very specific ethical questions regarding the ability to consent, what is considered public domain and what is considered private. As research in this area is increasing, interdisciplinary approaches to these ethical issues are also considered from multiple positions.