What is “threat framing”? It concerns how something or someone is perceived, labeled, and communicated as a threat to something or someone. The designation “threat,” notably, belongs to the wider family of negative concerns such as danger, risk, or hazard. Research on threat framing is not anchored in a single or specific field but rather is scattered across three separate and largely disconnected bodies of literature: framing theory, security studies, and crisis studies. It is noteworthy that whereas these literatures have contributed observations on how and under what consequences something is framed as a threat, none of them have sufficiently problematized the concept of threat. Crisis analysis considers the existence or perception of threat essential for a crisis to emerge, along with a perception of urgency and uncertainty, yet crisis studies focus on the meaning of “crisis” without problematizing the concept of threat. Likewise, security studies have spent a lot of ink defining “security,” typically understood as the “absence of threat,” but leave the notion of “threat” undefined. Further, framing theory is concerned with “problem definition” as a main or first function of framing but generally pays little or no attention to the meaning of “threat.” Moreover, cutting across these bodies of literature is the distinction between constructivist and rationalist approaches, both of which have contributed to the understanding of threat framing. Constructivist analyses have emphasized how threat framing can be embedded in a process of socialization and acculturation, making some frames appear normal and others highly contested. Rationalist approaches, on the other hand, have shown how threat framing can be a conscious strategic choice, intended to accomplish certain political effects such as the legitimization of extraordinary means, allocation of resources, or putting issues high on the political agenda. Although there are only a handful of studies explicitly combining insights across these fields, they have made some noteworthy observations. These studies have shown for example how different types of framing may fuel amity or enmity, cooperation, or conflict. These studies have also found that antagonistic threat frames are more likely to result in a securitizing or militarizing logic than do structural threat frames. Institutionalized threat frames are more likely to gain and maintain saliency, particularly if they are associated with policy monopolies. In the post-truth era, however, the link between evidence and saliency of frames is weakened, leaving room for a much more unpredictable politics of framing.