The current thesis presents a first step towards examining paranoia from a functional-analytic perspective. The focus of the research was ‘self-beliefs’ as a wealth of evidence in the existing cognitive-clinical literature suggests that this is a key process in the development and persistence of paranoia. From the functional-analytic perspective, paranoia and related self-concepts are defined as patterns of behaviour in context. The goal of this research involved elucidating these behaviours, determining how they influence each other, and identifying which contextual variables affect them. The work drew upon Relational Frame Theory (RFT), a functional-analytic theory of human language and cognition, and an RFT-based measure, the Implicit Relational Assessment Procedure (IRAP), to do so. Across five studies involving participants from the general (non-clinical) population, specific patterns of relational responding to the self that may be pertinent to paranoia were identified. Using an experimental approach involving threat-induction tasks, it was also demonstrated that paranoia and related responding to the self (e.g., as negative, vulnerable) and others (e.g., as trustworthy, devious) can be influenced by environmental factors. The IRAP was shown to be a useful measure in this regard, demonstrating predictive utility (Study 1), an ability to parse out patterns of responding relevant to high non-clinical paranoia (Study 4), and sensitivity to experimental manipulations (Studies 2, 3, and 5). Taken together, the findings from this research suggest that the functional-analytic perspective may compliment the cognitive-clinical approach to the study of paranoia and might also offer new and exciting avenues for research (e.g., novel procedures) in this domain.