Study objective: The impact of public health interventions during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic on critical illness in children has not been studied. We seek to determine the impact of SARS-CoV-2 related public health interventions on emergency healthcare utilization and frequency of critical illness in children. Methods: This was an interrupted time series analysis conducted at a single tertiary pediatric emergency department (PED). All patients evaluated by a provider from December 31 through May 14 of 6 consecutive years (2015-2020) were included. Total patient visits (ED and urgent care), shock trauma suite (STS) volume, and measures of critical illness were compared between the SARS-CoV-2 period (December 31, 2019 to May 14, 2020) and the same period for the previous 5 years combined. A segmented regression model was used to explore differences in the 3 outcomes between the study and control period. Results: Total visits, STS volume, and volume of critical illness were all significantly lower during the SARS-CoV-2 period. During the height of public health interventions, per day there were 151 fewer total visits and 7 fewer patients evaluated in the STS. The odds of having a 24-hour period without a single critical patient were >5 times higher. Trends appeared to start before the statewide shelter-in-place order and lasted for at least 8 weeks. Conclusions: In a metropolitan area without significant SARS-CoV-2 seeding, the pandemic was associated with a marked reduction in PED visits for critical pediatric illness.