BackgroundThe Omicron variant of SARS-CoV-2 has a predilection for the upper airways, causing symptoms such as sore throat, hoarse voice, and stridor. ObjectiveWe describe a series of children with COVID-19–associated croup in an urban multicenter hospital system. MethodsWe conducted a cross-sectional study of children ≤18 years of age presenting to the emergency department during the COVID-19 pandemic. Data were extracted from an institutional data repository comprised of all patients who were tested for SARS-CoV-2. We included patients with a croup diagnosis by International Classification of Diseases, 10th revision code and a positive SARS-CoV-2 test within 3 days of presentation. We compared demographics, clinical characteristics, and outcomes for patients presenting during a pre-Omicron period (March 1, 2020–December 1, 2021) to the Omicron wave (December 2, 2021–February 15, 2022). ResultsWe identified 67 children with croup, 10 (15%) pre-Omicron and 57 (85%) during the Omicron wave. The prevalence of croup among SARS-CoV-2–positive children increased by a factor of 5.8 (95% confidence interval 3.0–11.4) during the Omicron wave compared to prior. More patients were ≥6 years of age in the Omicron wave than prior (19% vs. 0%). The majority were not hospitalized (77%). More patients ≥6 years of age received epinephrine therapy for croup during the Omicron wave (73% vs. 35%). Most patients ≥6 years of age had no croup history (64%) and only 45% were vaccinated against SARS-CoV-2. ConclusionCroup was prevalent during the Omicron wave, atypically affecting patients ≥6 years of age. COVID-19–associated croup should be added to the differential diagnosis of children with stridor, regardless of age. © 2022 Elsevier Inc.