John Francis Leddy, OC (April 16, 1911 – September 17, 1998) was a Canadian academic and President of the University of Windsor from 1964 to 1978.

After attending the University of Chicago, doing graduate work in Latin and Greek from 1932 to 1933, he was elected a Rhodes Scholar at Oxford University (Exeter College), where he studied Ancient History, graduating Bachelor of Letters (B.Litt.)

From 1949 to 1964, he was also Dean of the College of Arts and Science, and from 1961 to 1964 Vice President (Academic).

In June 1961 at a Conference at McGill University Leddy along with Louis Perinbam, Keith Spicer, Guy Arnold established the organization Canadian University Service Overseas (CUSO) which sent young volunteers overseas to work on community development projects.

Due to his work with CUSO, Leddy was chosen by Prime Minister Lester B Pearson in 1965 to establish the Company of Young Canadians, which was also dubbed as Canada's version of the Peace Corps, even though its volunteers remained at home in Canada to work among disenfranchised communities (urban inner cities, First Nations reserves).