In 2005, Dr. Jennings was honoured for his dedication to saving lives by then‑NRC President Michael Raymont, who noted that Dr. Jennings "is one of those rare people who could, early on, see beyond the tables, numbers, and letters that intimidate so many young minds, and to recognize the patterns, the poetry, and the potential to create something new and exciting. We are delighted that he decided to bring this insight and wonder to the National Research Council here in Ottawa, but even more important, we are extremely grateful that he applied his wisdom and energy to issues of great public importance."
Over the years, Dr. Jennings has received numerous honours. In February 2015 at a ceremony at Rideau Hall, he was invested as Officer of the Order of Canada. He is also a Fellow of the Royal Society of Canada, the Infectious Disease Society of America and the Chemical Institute of Canada. He was a 2004 recipient of the SCI Kalev Pugi Award (Society of Chemical Industry), the 2003 Dr. Jonas Salk Award (Ontario March of Dimes) and the 2002 Manning Award of Distinction (Manning Foundation).