Klein, born November 19, 1942, was taught by his mother to love fashion. He would often accompany her when she went shopping in New York City for affordable clothes. From an early age he knew he wanted to be a fashion designer, and taught himself how to sketch and sew.
Before he turned twenty, he graduated from the Fashion Institute of Technology in New York. He married Jayne Centre and began working as an apprentice sketching European coat designs for his employer Dan Millstein to copy. Klein, however, disdained the idea that the normative American practice was to imitate European fashion and longed to start his own company. He believed that original fashion ideas could come out of the States and he was just the innovator to make it happen. But the realization of his dream seemed a long way away since he was struggling financially and was working part-time at his father’s grocery store in order to make some extra money