Leonardo was born to Jesus and Maria Zapata who raised him in San Antonio, Texas. He is the third of six children; has three brothers and two sisters. Leonardo graduated from Luther Burbank High School and the University of Texas at San Antonio. After receiving an Accounting degree, he worked at the U.S. Government Accountability Office (GAO) for 33 years. While at the GAO, Leonardo conducted program reviews and financial audits at federal agencies such as the Departments of Defense, Treasury, State, and Homeland Security.
Leonardo met his wife Janie in San Antonio. They married in May 1983. Janie gave birth to four daughters; two are deceased. They have six grandchildren, three boys and three girls. Leonardo and Janie have lived in southern Dallas County since 1989. They were active members of St. Francis of Assisi Catholic Church in Lancaster for 22 years. They have been parishioners at Holy Spirit since 2011.