Lea Stein (born 1931) is a French designer who creates jewellery and accessories from cellulose acetate (also known as rhodoid). Together with her husband she developed a process in which many very thin layers of cellulose acetate are finished with a laminating layer to form a sheet of multicoloured plastic. This sheet is then baked over a long period; once cooled, the multicoloured plastic is cut into shapes. The entire process can take up to six months. Lea Stein often incorporated different materials, such as lace, into her plastic, creating the beautiful patterns her jewellery is known for.

Lea Stein's jewellery falls into two periods: vintage (1969 to 1981) and contemporary (1991 to present). Every brooch has a V-shaped clasp marked 'Lea Stein Paris'.