Using corpus linguistics and qualitative, manual discourse analysis, this paper compares English and French extremist texts to determine how messages in different languages draw upon similar and distinct discursive themes and linguistic strategies. Findings show that both corpora focus on religion and rewards (i.e. for faith) and strongly rely on othering strategies. However, the English texts are concerned with world events whereas the French texts focus on issues specific to France. Also, while the English texts use Arabic code-switching as a form of legitimation, the French texts use a formal register and quotation from scripture in discussions of permissions, rights, obligations and laws. Finally, the English texts refer to and justify violence to a greater extent than the French texts. This paper contributes to the field of terrorism studies and the field of corpus linguistics by presenting a new approach to corpus-driven studies of discourse across more than one language. Keywords: English, French, cross-linguistic corpus analysis, extremism, corpus-driven discourse analysis