Lameness remains an ongoing challenge to the health and welfare of UK sheep flocks. Whilst effective recommended practice exists in the UK in the form of the five-point plan (5PP), it is not always used or used effectively, particularly in relation to culling. A more in-depth understanding of farmer lameness management behaviours and decision-making is crucial for driving positive change. Behaviour change frameworks offer useful tools to do this, specifically the Behaviour Change Wheel and its central tenets of capability, opportunity and motivation (COM-B). This research sought to explore on-farm management practices surrounding lameness, particularly focused on the 5PP and culling in relation to COM-B. Findings are drawn from five online focus groups with UK farmers (n = 19) and one with veterinarians (n = 4). Thematic analysis led to the identification of themes in relation to the role of capability, opportunity and motivation to enact the steps of the 5PP, particularly culling. Culling, alongside prompt treatment, were the only tools used by all participants. Yet, culling practices did not always follow recommended advice. Factors that influenced behaviours included those self-controlled by farmers, e.g. records kept; outside of their control, e.g. space available, and those controlled by other actors, such as market prices. Considerations of the individual farm and the wider UK sheep sector context were important. Findings suggest a need for interventions aimed at encouraging good record-keeping, collective industry action against lameness and opportunities for vet-farmer interactions. These should be pursued together to achieve the goal of reducing lameness and subsequently improving sheep welfare.