John D. Leslie was born in Calgary, AB, on January 4, 1918, and died on April 18, 2022. While he was still young, the family moved to Vancouver, which he considered home. Although his family faced many economic challenges, at age 17 John was able to begin his studies at UBC. He was the highest ranking student in the applied science graduating class and won the Lefevre Gold Medal and Scholarship.

In 1942 he married Patricia Cumming, also a UBC graduate, and they moved to Ottawa, where a daughter was born. After WWII the family moved to New Jersey where John began his engineering career with Standard Oil. Two more children followed and the family moved to California, settling in the San Francisco Bay Area, where John worked for Shell Development.

In 1957 John was recruited by a UBC colleague, F. Cam Williams, to teach petroleum processing in Rio de Janeiro, Brazil, where the family lived for three years. He returned to the United States to work for Bechtel Corporation in San Francisco, later transferring to the London office, which provided, in addition to engaging work, opportunities for extensive travel. Returning to the United States, John continued working in the oil refining industry, only retiring at age 80.

John lived out his retirement near his daughter in the Bay Area. He is survived and deeply missed by his three children, six grandchildren, 10 great-grandchildren, and extended family.