This dissertation examines the social history of interpreters and their ambivalent position in colonial Vietnam from 1862 to 1945. As a group, colonial interpreters were reputed to be untrustworthy, dubious and corrupt. They have a negative assessment in Vietnamese historiography in that they have been positioned through the binary of resistance and collaboration. In order to understand their ambivalent position I argue that it is necessary to examine the institution that produced them along with their social relationship with both the local population and the administration. Occupying the zone of contact, interpreters were able to manipulate their language skills to permeate the colonial system; their ability to control, transmit and alter information made them powerful agents. The colonial administration attempted to monitor their translation activities through linguistic surveillance, legal apparatus and disciplinary means, whereby mistranslation was criminalized. Yet, their efforts were not always effective. The dissertation also problematizes the issues of subjectivity and neutrality by examining the political radicalization of an interpreter, Đồng Sỹ Hứa during his time in the New Hebrides. Lastly, I discuss the unintended consequences of implementing quốc ngữ as the intermediary script within the three-tier translation regime that engendered its formation and political construction as the 'national script' of Vietnam by 1945.