Mary-Kate Olsen, born June 13, 1986, is an American fashion designer, former actress and producer. She began her acting career nine months after her birth, sharing the role of Michelle Tanner with her twin sister Ashley Olsen in the television sitcom Full House (1987–1995). They also starred in numerous films together.
She and her twin sister, Ashley Olsen, co-founded luxury fashion brand The Row, lifestyle brand Elizabeth and James, and more affordable fashion lines Olsenboye and StyleMint. They are members of the Council of Fashion Designers of America.
She is also related to Elizabeth Olsen.