UHN is home to Canada's largest biomedical research institute. Its five research institutes are located at UHN's four member hospitals:

• Ontario Cancer Institute
  Director: Dr. Benjamin Neel
  
  Advanced Medical Discovery Institute
  Director: Dr. Tak Mak
  The Campbell Family Cancer Research Institute
  Director: Dr. Benjamin Neel
  The Campbell Family Institute for Breast Cancer Research
  Director: Dr. Tak Mak

• Techna Institute
  Director: Dr. David Jaffray

• Toronto General Research Institute
  Director: Dr. Mansoor Husain

• Toronto Rehabilitation Institute
  Director: Dr. Geoff Fernie

• Toronto Western Research Institute
  Interim Director: Dr. Peter Carlen

As hospital-based centres, all five UHN institutes pursue a clinically-relevant program of research that spans the spectrum from basic discovery research to translational research to clinical research. Appointees include scientists and clinician-scientists.

UHN institutes and researchers are affiliated with the University of Toronto. UHN researchers comprise approximately 18% of the University of Toronto medical faculty.