As of September 2021, children have stated the new school year and Canada has entered the fourth wave of the pandemic (18, 19). Delta is the dominant variant across Canada and the number of and proportion of Delta cases is increasing across the country and modelling studies have predicted that the daily number of cases may double in the next month (19). Evidence is just beginning to emerge on the effects of the Delta variant on children. To further inform public health strategies to protect children including in school settings, this evidence brief summarizes what is known on the virulence, transmission and impact of Delta among children aged 0-17 years old including the impact of public health interventions. This report presents evidence up to September 14, 2021.