Theresa Tam

Theresa Tam (; born 1965) is a Canadian physician and public servant who served as the chief public health officer of Canada (CPHO), the second-in-command of the Public Health Agency of Canada (PHAC). Tam initially took the role as acting CPHO following the retirement of her predecessor, She was formally appointed on June 26, 2017. She stepped down as CPHO on June 20, 2025.

Tam has played a leadership role in Canada's response to public health emergencies, including SARS, H1N1, MERS, Ebola, and COVID-19. She has also worked towards eradicating polio. Tam was born in British Hong Kong and later grew up in the United Kingdom. She attended medical school at the University of Nottingham, earning an MBBS 1989. In 1996, She completed her pediatric residency at the University of Alberta, and in 1997, a pediatric infectious diseases fellowship at University of British Columbia.

Since 1996, Tam has been a fellow of the Royal College of Physicians and Surgeons of Canada. In 2003, Tam was the chief of Health Canada's immunization and respiratory infections division during the SARS outbreak. which envisioned a respiratory infection pandemic that was described in The Globe and Mail as foreshadowing the COVID-19 pandemic "with eerie accuracy." At that time in 2006, she was Director of the Immunization and Respiratory Infections Division at the PHAC.

Tam is on the Independent Oversight and Advisory Committee of the Health Emergencies Programme of the World Health Organization (WHO), a role she took up between April and June 2018. She is an official advisor to the WHO's International Health Regulations Emergency Committee on 2019-nCoV.

In 2019, Tam criticized people who refuse vaccines, saying "They're a small number, but they're spreading misinformation." "And they're communicating their opinions in a very emotional way." On January 23, Tam was a member of the WHO committee that broadcast that it was too early to declare a public health emergency of international concern.

As the pandemic progressed and as was typical at the time, as the Chief Public Health Officer of Canada, she made numerous statements that garnered attention, both positive and negative, from the public and from some politicians. Some statements proved to be minimising of the effects of COVID-19, On April 6, Tam changed her recommendation to "wearing a non-medical mask, even if you have no symptoms, as an additional measure that you can take to protect others around you in situations where physical distancing is difficult to maintain" because of new data about pre-symptomatic and asymptomatic transmission.

In February 2021, an Auditor General's report stated that the Public Health Agency of Canada underestimated the threat posed by COVID-19 to Canadians. In particular, it was noted that the Agency "did not consider forward-looking pandemic risk" when it concluded that COVID‐19 would have a minimal impact if an outbreak were to occur in Canada.