Plekon's interest in studying religion began early on when he chose to pursue a bachelor's degree in Sociology and Philosophy from the Catholic University in Washington, D.C. in 1970. He later obtained a master’s degree and a doctorate in Sociology and Religion from Rutgers University in New Jersey. Plekon's doctoral advisor was renowned sociologist of religion and theologian Peter L. Berger, who mentions Plekon in his memoir among his students of interest as an "expert in the Orthodox (Christian) diaspora in the West.". Plekon met his wife Jeanne through a long-time friend while she was pursuing a master's in art history and museum studies at The Clark Institute, Williams College. They have been married since 1976 and have two children, Paul and Hannah. Plekon has received more than twenty research awards in his years at Baruch College-CUNY, including annual PSC-CUNY Faculty Research Awards, several Baruch Faculty Fellowships for a year of study and other research grants.