Jefferson Thomas Hennessy Sr. (October 27, 1929 – March 24, 2015) was trampoline coach and physical educator. He was an Associate Professor of Physical Education at University of Louisiana at Lafayette from 1959 to 1986, served as the director of the University’s gymnastics and trampoline programs and he was the United States trampolining coach from 1964 to 1980. In total, his athletes were awarded 26 world championship medals and numerous national and regional titles and medals.