He was born in Manhattan to Spanish parents who were both born in Barcelona. He grew up in the United States, Mexico, and Europe and attended the exclusive private Swiss school, Institute Le Rosey. He opened his first modelling agency in or shortly after 1969.
His company, John Casablancas modeling and acting school, now has franchises in Bolivia, Peru, the Dominican Republic, Italy, and Indonesia, as well as in the United States, for example in Florida, New York, New Mexico, and Arizona. As owner of this company, he used to state the advantages of the contacts he had with the Elite Modeling agency.
He reportedly left Elite Modeling in 2000, and now he heads the John Casablancas Career Center. Since he left Elite, many rumors of his company being fraudulent have surfaced. So far, however, nothing has surfaced to back up the rumors.
He is the father of Julian Casablancas, lead singer of the band The Strokes.