John Klein is an American businessman and philanthropist, a Holocaust survivor born in Hungary who survived the Auschwitz concentration camp during World War II. After the war, he immigrated to the United States in the early 1950s and established a successful career in business, reportedly in real estate and investments. He is best known for co-founding the Friends of the Israel Defense Forces (FIDF) in 1981, serving as its initial chairman, and playing a pivotal role in building the organization into a major nonprofit that provides educational, social, and financial support to IDF soldiers and their families, raising millions of dollars annually. His philanthropy is deeply rooted in his personal history of survival and resilience, and he has been actively involved in Holocaust education and remembrance, sharing his story to combat antisemitism and support Israel's defense capabilities. Klein's leadership in FIDF has connected him to influential networks within Jewish and pro-Israel communities in the United States. He maintains a low public profile outside of his charitable endeavors, focusing on family and business while avoiding personal controversies, and remains a respected figure in these circles despite his age.