OBJECTIVE To understand the current state of emergency department (ED) influenza vaccine programs across the US and characterize children receiving ED vaccines. METHODS This was a retrospective study of encounters with an influenza vaccine administration in 44 hospitals in the Pediatric Health Information System, from September 2016 to March 2023. We described institutional variation in ED influenza vaccine administration and compared it with rates of vaccination during hospitalizations. We identified demographic factors associated with receiving an influenza vaccine during an ED visit, using generalized linear mixed-effects models. RESULTS There were 46 901 ED encounters with an influenza vaccine administration, but these were clustered in just a few EDs (96% were administered in 14 EDs). During influenza seasons, the median ED administered 0.4 influenza vaccines per 1000 ED encounters (IQR 0.1-2.1; range 0-39.9 per 1000 encounters). ED vaccination rates were considerably lower than rates for hospitalizations (median 61 per 1000; IQR: 39-94). Compared with ED visits without a vaccine, there were greater odds of influenza vaccination during an ED visit for children that were older, Hispanic (odds ratio [OR] 1.81; 95% CI: 1.73-1.91), Non-Hispanic Black (OR 1.71; 95% CI: 1.62-1.80), Medicaid insured (OR 1.45; 95% CI: 1.39-1.52), and from very low childhood opportunity index areas (OR 1.59; 95% CI: 1.50-1.69). CONCLUSIONS Influenza vaccine administration rates in the ED were low. Although only a few EDs regularly provided influenza vaccines, they reached traditionally undervaccinated pediatric populations. Future work should assess how ED vaccination programs might complement current hospital and primary care efforts to improve vaccine access.