ABSTRACT: The aim of this paper is to relate two trending topics in contemporary epistemology: the discussion of group knowledge and the discussion of knowledge-first approach. In social epistemology no one has seriously applied and developed Williamson’s theory of knowledge-first approach to the case of group knowledge yet. For example, scholars of group knowledge typically assume that knowledge is analyzed in terms of more basic concepts, such as group belief or acceptance, group justification, and so on. However, if Williamson’s theory of knowledge is correct, these are not good analyzes for understanding group knowledge. For, in such framework, knowledge is not analyzed in terms of belief and justification, and the same should apply to group knowledge. Thus, we propose to analyze which consequences Williamson’s theory has for social epistemology, namely for an understanding of group knowledge. The questions that will guide this article are the following: What is a knowledge-first approach to group knowledge? And what does a knowledge-first approach teach us with regard to one of the most pressing issues of social epistemology, namely the dispute between summativists and non-summativists accounts of groups? We claim that a knowledge-first account of group knowledge can be offered and that it favors non-summativism.