This repository will host anonymized data collected for the study titled "Personality Matters: Exploring the Relationship Between Personality and Stress Physiology in Captive African Lions" as part of the PhD research requirements. The study was conducted between June and August 2018 and May to December 2019 on twenty-two captive African lions, which were rated by their caretakers at two locations in NSW. This research was approved by the Animal Care and Ethics Committee at Western Sydney University, New South Wales (A12772). The data collection methods included big cat behavioural observations, an animal personality checklist, thermal assessment and glucocorticoid assessments using faecal cortisol analysis. The personality traits for the lions were rated on a 7-point Likert scale, where 1 represents “not at all” and 7 represents “very much”, describing the degree to which a behaviour is seen in an animal. This data is now published as a journal article and can be accessed at: Vaz, J., Bartley, A. & Hunt, J. Personality matters: exploring the relationship between personality and stress physiology in captive African lions. BMC Zool 7, 30 (2022). https://doi.org/10.1186/s40850-022-00126-9