This presentation will describe modelling conducted by the Public Health Agency of Canada. It will include modelling at the outset of the epidemic to assess the national risk COVID-19, modelling that aimed to provide intelligence of the trajectory of the epidemic, to guide how NPIs other than restrictive closures could be used to control the epidemic and, if restrictions were necessary, how best to use them. Modelling also provided guidance on when restrictions could be lifted as the vaccinations rolled out. More recently modelling has focused on the impacts and responses to the epidemic waves caused by the delta and omicron variants of concern. The presentation aims to stimulate discussion of hurdles to modelling, and the degree to which modelling impacted policies during the COVID-19 pandemic.