Born into a Sephardic Jewish family originating from Toledo, Spain, Benhamou left Algeria in 1960 with his parents during Algeria's independence war. His family settled in Grenoble, France, where he grew up and attended Lycée Champollion. He continued his studies in Paris and graduated with a "diplôme d'Ingénieur" from École nationale supérieure d'arts et métiers (Ai. 172), the youngest student to receive this degree. He subsequently was awarded a doctorate. In 1976, at the age of 20, Benhamou emigrated to the United States and enrolled at Stanford University. He graduated with a Master of Science degree.