Aims To provide an overview of reported cases of new-onset type 1 diabetes mellitus (T1D) following COVID-19 infection. Methods PubMed and Scopus library databases were screened for relevant case reports published between January 2020 and June 2022. Study design, geographic region or language were not restricted. Results Twenty studies were identified and involved 37 patients (20 [54%] male, 17 [46%] female). Median age was 11.5 years (range 8 months–33 years) and 31 (84%) patients were aged ≤17 years. Most patients (33, 89%) presented with diabetic ketoacidosis (DKA). In total, 23 (62%) patients presented at the time of positive COVID-19 testing and 14 (38%) had symptoms consistent with COVID-19 infection or a previous positive test (1–56 days). Diabetes symptomatology was provided in 22 cases and (19, 86%) reported polyuria, polydipsia, polyphagia, fatigue, or weight loss or a combination of the aforementioned in the preceding weeks (3 days–12 weeks). Of the 28 patients that had data on acute and long-term treatment, all recovered well and most were managed with basal bolus insulin regimens. Quality assessment showed that most reports were either ‘good’ or ‘moderate quality’. Conclusions Although uncommon, new-onset T1D is a condition healthcare professionals may expect to see following a COVID-19 infection.