Mary Theresa Eleanor Higgins Clark (December 24, 1927 – January 31, 2020) was an American author of suspense novels. Each of her 51 books was a bestseller in the United States and various European countries, and all of her novels remained in print as of 2015, with her debut suspense novel, Where Are the Children?, in its seventy-fifth printing.
Higgins Clark began writing at an early age. After several years working as a secretary and copy editor, she spent a year as a stewardess for Pan-American Airlines before leaving her job to marry and start a family. She supplemented the family's income by writing short stories. After her husband died in 1964, Higgins Clark worked for many years writing four-minute radio scripts until her agent persuaded her to try writing novels. Her debut novel, a fictionalized account of the life of George Washington, did not sell well, and she decided to exploit her love of mystery/suspense novels. Her suspense novels became very popular, and have sold more than 100 million copies in the United States alone. Her daughter Carol Higgins Clark and former daughter-in-law Mary Jane Clark, are also writers.
She is also known as Mary Theresa Eleanor Higgins Clark Conheeney.