Virtual exchange (VE) is an ideal venue for digital literacy skills development (Fuchs, Hauck & Müller-Hartmann, 2012) and for critical digital literacy (CDL) (Hauck, 2019). Yet literacy is a fluid, deictic term, the meaning of which is context dependent, and digital literacies need to be defined and conceptualised within a specific context. Recent CALL literature highlights the interest in CDL from various perspectives, but how CDL is conceptualised by the VE participants themselves is not explored. Participants of this study were 37 trainee English language teachers in the UK and Turkey who joined a 6-week VE. Their ongoing reflections on CDL were captured through reflective e-portfolio entries following each VE task. Thematic analysis revealed four components of CDL in this specific VE: (1) participants' awareness of digital affordances for "self-expression," (2) semiotic and interactional means to "build connections," (3) ensuring "inclusiveness" of all community members, and (4) implications of "socio-political contexts" of each participant for meaning-making and interaction. We conclude that in future pedagogical implementations of VE, facilitators can foster trainee teachers' CDL development through more closely guided and informed reflection on the four themes presented in this paper. As such, this study makes a novel contribution to our understanding of CDL in VE settings for ELT teacher education by offering a social semiotic second language acquisition orientation within an interpretivist paradigm.