Currently, the world is facing two serious pandemics: obesity and COVID-19. It is well-established that the prevalence of obesity has risen dramatically, causing a deterioration in the health quality of the population and increasing susceptibility for the unfavourable course of acute infections. It has been observed that excess body mass significantly influences the COVID-19 outcome. The aim of this review is to present the latest scientific reports on the impact of excess body mass on the course and complications of COVID-19. The Web of Science, PubMed, and Google Scholar databases were searched. Only studies reporting patients stated to be COVID-19 positive based on the results of a nasopharyngeal swab and the ribonucleic acid test were included. It is shown that thromboembolic and ischemic complications, namely stroke, disseminated intravascular coagulation, severe hyperglycaemia, and leukoencephalopathy are more likely to appear in COVID-19 positive patients with obesity compared to non-obese subjects. COVID-19 complications such as cardiomyopathy, dysrhythmias, endothelial dysfunction, acute kidney injury, dyslipidaemia, lung lesions and acute respiratory distress syndrome have a worse outcome among obese patients.