She attended the independent Summerhill School in Leiston, Suffolk, England before completing her studies at a private high school in Germany. After his death, De Mornay and her stepbrother were raised by her mother, who relocated the family to Europe, where they lived in several different locations. She spent her early years in Pasadena, California, until her stepfather died of a stroke on March 2, 1962, aged 48. Her parents divorced in 1960, and she took the surname of her stepfather, Richard De Mornay, after her mother married him in 1961. Her paternal grandmother was vaudeville performer and child film actress Eugenia Clinchard. Her parents were Julie and Wally George ( né George Walter Pearch), a disc jockey and later television host.
De Mornay was born Rebecca Jane Pearch in Santa Rosa, California on August 29.
