In the contemporary context, where volunteering constitutes a significant element of social and political dynamics, examining its legal framework provides deeper insights into the mechanisms shaping and advancing civil society. This study aimed to determine the discourseforming role of the concept VOLUNTEER in international (UN) and national (Ukraine, USA, Russia) regulatory documents. To achieve this goal, both general scientific methods (analysis, synthesis, generalisation) and linguistic research methods were employed. Discourse analysis was used to identify common and distinctive features in the positioning of the concept VOLUNTEER within international and national regulatory documents. Concept analysis facilitated the exploration of the concept’s development in both diachronic and synchronic dimensions. The findings revealed that its positioning within national discourses serves as an indicator of a fully developed volunteering discourse, understood as a type of social behaviour based on the interaction between volunteers and beneficiaries. This discourse exhibits both national and international manifestations, is culturally conditioned, and operates within the legitimate norms and regulations governing volunteering activities in the respective countries. It is noted that UN regulatory documents on volunteering establish the strategic pragmatics of the volunteering discourse and position universal conceptual-thematic groups of the lexical verbaliser volunteer. A comparison of the conceptual-thematic groups represented in UN regulatory documents and those in the legal frameworks of the countries under study has enabled the identification of alignments between fragments of national conceptual worldviews and the international value system. The study demonstrates that the concept VOLUNTEER plays a discourse-forming role in UN resolutions as well as in the legal documents of Ukraine and the USA concerning volunteer activities. The militarisation of the concept VOLUNTEER in Russian documents reflects the discursive behaviour of the state institutions of an aggressor country, aimed at fostering conflict, war, and the militarisation of society. The findings of this research can be applied in educational contexts, particularly in teaching courses such as Text Linguistics and Strategic Communications, as well as in the development of legal frameworks for volunteering activities