Colombia has experienced the longest civil conflict in the Western Hemisphere. Among the many actors in this conflict is a diverse array of left-wing groups espousing various political and ideological approaches. The left of the political spectrum in the Colombian conflict is so diverse, it is useful to use the concept of extremism while being mindful of both its applications and limits. First, the concept of extremism is discussed and operationalized, based on the particularities of the Colombian case. Second, through interviews and secondary sources, we identify the diversity of expressions of left-wing ideological extremism in the Colombian conflict and explore if their extremism necessarily adopted violent routes or was expressed in nonviolent political strategies. Our analysis could expose that extremism not only impacts violent radicalization and conflict reproduction but can be a radical way of expressing nonviolent political positions in contexts where left-wing expressions have traditionally been stigmatized. This approach to the relationship between extremism, politics and violence could ease the recognition of political perspectives that were marginalized but whose recognition is needed for constructing and expanding a more democratic and political regime in Colombia.