Mary Elizabeth Winstead was born in Rocky Mount, North Carolina, to Betty Lou (née Knight) and James Ronald Winstead.

Her family moved to Sandy, Utah, where she attended Peruvian Park Elementary and took advanced classes.

She studied dance in a Joffrey Ballet summer program in Chicago and sang in the International Children's Choir.

After realizing a dance career was unlikely due to her height, she turned to acting and was homeschooled through most of high school.