Born in New York City and raised in Washington Township, Bergen County, New Jersey,[1] Clark attended Immaculate Heart Academy.

While Mary Higgins Clark attempted juggling a full-time job and trying to finish her second book, the younger Higgins Clark grasped this opportunity to familiarize herself with the process of writing a book and telling tales, not knowing this would be her start in becoming a well-known author.

[5] All of her novels feature Regan Reilly (a famous recurring character), plot points about male escorts, and pantyhose conventions that come from real sources.

[6] In her video for NJN Public Television, Clark explains how she used her first job experience to help her with ideas about her book.

[10] On June 12, 2023, Clark died at Cedars-Sinai Medical Center in Los Angeles of appendix cancer at the age of 66.