INTRODUCTION: COVID-19 is a novel coronavirus that emerged from Wuhan, China in December 2019, and within 3 months became a global pandemic. AREAS COVERED: PubMed search of published data on COVID-19, respiratory infections, and diabetes mellitus (DM). DM associates with impairments of both cellular and humoral immunity. Early emergent global data reveal that severity of clinical outcome from COVID-19 infection (including hospitalization and admission to Intensive Care Unit [ICU]), associate with co-morbidities, prominently DM. The key principles of management of COVID-19 in patients with DM include ongoing focused outpatient management (remotely where necessary) and maintenance of good glycemic control. EXPERT OPINION: We will remember the dawn of the third decade of the twenty-first century as a time when the world changed, the true scale and impact of which is hard for us to imagine. Like a phoenix from the ashes though, COVID-19 provides us with a great learning opportunity to renew insights into ourselves as individuals, our clinical teams, and the optimized provision of care for our patients. COVID-19 has re-shaped and re-focused our collective societal values, with a sea-changed shift from materialistic to human-centric, from self-centredness to altruism, ultimately for the betterment of patient care and the whole of society.