Hooper joins the department store business from Hong Kong-based supplier Silvereed where she was UK managing director. She was also previously buying and design director at East and head of buying and design at Debenhams.
Hooper will oversee buying across all the womenswear and lingerie at John Lewis, including the branded and own brand offer.
She will report to fashion buying director Peter Ruis and will be the first womenswear buying director since the restructure of the company's fashion buying team last June.
Hooper's appointment completes a clothing buying team which also includes head of buying for menswear and sports Adrian Edwards who was appointed in October.