UNLABELLED: Patient and Public Involvement (PPI) describes the active involvement of patients and the public in the research process. Through PPI, patients and members of the public are increasingly involved in the design and conduct of clinical trials. PPI has been shown to improve the quality and relevance of research. During the COVID-19 pandemic, clinical trials have been playing a vital role in helping us find ways to prevent and treat the infection and improve our understanding of the virus. It is important that patients and the public are actively involved in deciding how COVID-19 research is carried out. Unfortunately, Research Ethics Committees in the UK have seen far less PPI for COVID-19 research studies compared with research before the pandemic. A key reason for this is that research is being designed much faster than normal and researchers may feel they do not have time to properly involve patients and the public. In this paper, we share our experiences of PPI for a COVID-19 clinical trial. We show that it is possible to rapidly involve patients and the public in COVID-19 clinical trials. We also explain how the design of the clinical trial was changed in response to feedback from public contributors. Lastly, we discuss the wider learning from this process which might be useful for researchers planning PPI activities for COVID-19 clinical trials in the future. BACKGROUND: Clinical trials are playing a critical role in the global public health response to the COVID-19 pandemic. Despite the increasing recognition of the value of PPI in clinical trials, just 22% of the COVID-19 research proposals reviewed by Research Ethics Committees in the UK at the start of the pandemic reported PPI. There is a perception that PPI might result in delays in delivering research and therefore delays in obtaining important results. In this paper, we report our experience of rapid PPI for a COVID-19 clinical trial. METHODS: RAPID-19 is a COVID-19 clinical trial which was planned to be submitted for fast-track ethics review in the United Kingdom. During the development of the trial protocol, the PPI Panel at the London School of Hygiene & Tropical Medicine Clinical Trials Unit was involved in the design of the study. The meeting with the PPI Panel lasted just over 1 h and was conducted by teleconference. RESULTS: Although we only had a short period of time to explore the study with the PPI Panel, we were able to gain valuable insight into how the trial would be perceived by potential trial participants. Substantive changes were made to the trial to improve the acceptability of the research without compromising the study timelines. Having access to public contributors with relevant lived experience is an important resource for a Clinical Trials Unit and is critical for rapid PPI. The move to remote working due to lockdown required virtual discussions which helped to overcome some of the barriers to organising face-to-face meetings at short notice. CONCLUSIONS: PPI for clinical trials can be conducted in a time-efficient manner within the pressured environment of a pandemic. Involving PPI contributors at an early stage in protocol development maximised the opportunity to shape and influence the trial as well as limited potential delays which could occur if changes to the protocol had to be made at a later stage.