Lois Duncan grew up in Sarasota, Florida, the daughter of internationally known magazine photographers, Joseph and Lois Steinmetz.
From early childhood, she knew she wanted to be a writer. She submitted her first story to a magazine at the age of ten and made her first sale at thirteen to a magazine called Calling All Girls. Throughout her high school years she wrote regularly for young people's magazines, particularly Seventeen.
In 1962, Lois moved to Albuquerque, New Mexico, where she taught for the Journalism Department at the University of New Mexico and continued to write for magazines. Over 300 of her articles and short stories appeared in such publications as Ladies Home Journal, Redbook, McCall's, Good Housekeeping, and Reader's Digest, and for a number of years she was a contributing editor for Woman's Day.
Lois was the author of 48 books, ranging from children's picture books to adult novels, but she is best known for her young adult suspense novels.
Some of her works were adapted for the screen, the most famous example being the 1997 film I Know What You Did Last Summer, adapted from her novel of the same title. In interviews she stated her distaste at her young adult novel becoming a horror comedy film.
Many of her YA books have been chosen as American Library Association "Best Books for Young Adults" and Jr. Literary Guild Selections, and they have won Young Readers Awards in 16 states and three foreign countries. In 1992, Lois received the Margaret A. Edwards Award, presented by the School Library Journal and the Young Adult Library Services Association, to honor a living author for a distinguished body of adolescent literature.
Lois Duncan also wrote novels and non-fiction books for adults, including Who Killed My Daughter?, the true story of her search for the truth behind the brutal murder of the youngest of her five children, eighteen-year-old Kaitlyn. Although written for adults, this book has been embraced by young people.
She was named Mystery Writers of America Grandmaster Award in 2015. Well deserved. Her books were an inspiration to so many other writers.