This article explores the concept of ‘human security’: the idea that the referent object and beneficiary of security should be individuals. It demonstrates that the concept has had some success as a normative reference point for human-centred policy movements internationally, and it reflects a broader shift towards human agency and human-centred conceptions of security. As a theoretical concept, therefore, the idea contributes to a multi-disciplinary reconceptualization of security that draws upon theoretical debates in political science and criminology. However, attempts to operationalize it have exposed fundamental problems in the new security discourse more broadly, generating critiques in political science and criminology which share common foundations but which are rarely engaged in an integrated manner. This article explores whether critical or radical security ideas like human security can be reconciled with political ‘realities’ or whether this undermines their intellectual integrity. In addressing this debate from an international relations perspective, the article also engages with criminological scholarship on security in order to identify and strengthen links across the disciplines.