John J. Caleca, III was born and raised in Pohatcong Towhship, Phillipsburg, New Jersey. He graduated from Phillipsburg High School and attended college locally at East Stroudsburg University. In 1999, he received his law degree from Seton Hall University.
After graduating from college, he enlisted in the United States Marine Corps. While on active duty, he was recruited to attend the Marine Corps Officer Candidate School, but chose to go to law school instead.
Prior to opening his own law firm, he worked for a plaintiff's firm in Clark, New Jersey and a defense firm in Morristown, New Jersey. Also, he worked for the State of New Jersey for a number of years as the Chief of Staff and Counsel to a Commissioner at the New Jersey Board of Public Utilities.