This year marks the 15th anniversary of Severe Acute Respiratory Syndrome (SARS) in Canada and the 100th anniversary of the 1918 Spanish influenza pandemic. These, and other recent public health events, provide an opportunity for us to review and reflect on the evolution of Canada’s public health emergency response over the past 15 years—from SARS, to the 2009 H1N1 pandemic influenza, to Ebola virus and Zika virus disease. Key lessons have been learned and milestones achieved that have shaped and sharpened our response approach and structures. While SARS was a wake-up-call to strengthen infection prevention and control capacity in health care settings and led to the formation of the Public Health Agency of Canada, it also strengthened our Federal/Provincial/Territorial (FPT) senior-level governance and led to agreements for pan-Canadian mutual aid and infectious disease information sharing. As well, our collective public health laboratory capacity has been strengthened through ongoing response and sharing of advanced diagnostics and research. As we move forward, it will be important to explore the design of scalable or modular emergency response strategies and structures that are socio-culturally appropriate and employ evidence-based strategic risk communications that continue to be critical, especially given the volume and spread of misinformation. With the current global reality, we must recognize that public health threats that go unchecked anywhere in the world have the potential to very rapidly become a public health threat in Canada. We need to build, maintain and share our best public health practices globally, for we neglect these at our peril.