Hart was born Carolyn Gimpel and was raised in Oklahoma City, Oklahoma, where she still lives. She attended Cleveland Elementary School, Taft Junior High School, and Classen High School. At the age of 11, Hart decided that she wanted to be a newspaper reporter. She worked on school papers beginning in grade school, continuing all the way through her college years.
Hart is a Phi Beta Kappa graduate of the University of Oklahoma (class of 1958), where she majored in journalism. Hart met her husband, Philip, while traveling in Europe in her junior year in college. After graduation, while her husband attended law school, Hart worked as a reporter for The Norman Transcript. She gave up journalism after the birth of her son, Philip Jr.
In 1964, the year her daughter, Sarah, was born, Hart won a writing contest calling for a mystery novel that would appeal to adolescent girls, sponsored by Dodd, Mead and Calling All Girls. She went on to write several more teenage and young adult mysteries between 1965 and 1972. From 1972 to 1987, she wrote nine stand-alone suspense novels and mysteries which had only modest success. Until the publication of books by Marcia Muller, Sara Paretsky, and Sue Grafton, publishers had little interested in mysteries written by female American authors. The success of these authors opened the door for Hart's Death on Demand series in 1987.
Hart's stand-alone World War II novel Letter from Home was nominated for the Pulitzer Prize for Fiction by the Oklahoma Center for Poets and Writers at Oklahoma State University–Tulsa. She has twice appeared as one of the featured mystery authors at the Library of Congress National Book Festival in Washington, D.C. 
Hart has won awards throughout her four-decade writing career.
- Mystery Writers of America Grand Master 2014
- Agatha Award - nine nominations and three wins
- Anthony Award for Best Paperback Original - five nominations and two wins
- Macavity Award for Best Paperback Original - two wins
- Ridley Pearson Award for significant contribution to the mystery field
- Guest of Honor at the Malice Domestic annual conference in 1997 and recipient of its Lifetime Achievement Award in 2007
- Oklahoma Center for the Book award for fiction in 2001 and Lifetime Achievement Award in 2004
- Distinguished Alumnus of the Gaylord College of Journalism and Mass Communication
- Appeared as a featured mystery author at the Library of Congress National Book Festival on the Mall in Washington DC in 2003 and 2007
- member and past president of Sisters in Crime
Death on Demand
Hart's first commercially successful adult mystery series features Annie Laurance, proprietor of the Death on Demand bookstore, located in the fictional South Carolina island community of Broward's Rock. By using a mystery bookstore for her background, Hart has given her characters the opportunity to talk freely about other mystery authors and books. One of the ongoing themes of the series is a contest whereby the first customer who correctly identifies a series of five mysteries from the clues in a painting hanging in the shop wins his or her choice of a novel.
- Death on Demand (1987)
- Design for Murder (1988)
- Something Wicked (1988)
- Honeymoon with Murder (1988)
- A Little Class on Murder (1989)
- Deadly Valentine (1990)
- The Christie Caper (1991)
- Southern Ghost (1992)
- Mint Julep Murder (1995)
- Yankee Doodle Dead (1998)
- White Elephant Dead (1999)
- Sugarplum Dead (2000)
- April Fool Dead (2002)
- Engaged to Die (2003)
- Murder Walks the Plank (2004)
- Death of the Party (2005)
- Dead Days of Summer (2006)
- Death Walked In (2008)
- Dare to Die (2009)
- Laughed 'Til He Died (2010)
- Dead by Midnight (2011)
- Death Comes Silently (2012)
- Dead, White and Blue (2013)
- Death at the Door (2014)
- Don't Go Home (2015)
- From the Queen (2015)
- Walking on My Grave (2017)
Hart's Henrie O mysteries feature 70-something retired newswoman, Henrie O'Dwyer Collins, as she travels the country and the world, solving crimes that seem to follow her as she travels. Henrie gets by on her grit, tenacity, and sensible shoes.
- Dead Man's Island (1993), turned into a 1996 TV movie starring Barbara Eden and William Shatner
- Scandal in Fair Haven (1994)
- Death in Lovers' Lane (1997)
- Death in Paradise (1998)
- Death on the River Walk (1999)
- Resort to Murder (2001)
- Set Sail for Murder (2007)
Bailey Ruth Raeburn
Hart's newest protagonist, the ghost of a woman killed at sea who returns to earth via the "Rescue Express" to help her fictional hometown of Adelaide, Oklahoma while trying not to violate the Precepts for Earthly Visitation and adjusting to her powers on earth.
- Ghost at Work (2008)
- Merry, Merry Ghost (2009)
- Ghost In Trouble (2010)
- Ghost Gone Wild (2013)
- Ghost Wanted (2014)
- Ghost to the Rescue (2015)
- The Secret of the Cellars (1998, ebook 2013)
- Dangerous Summer (1968, ebook 2013)
- No Easy Answers (1970, reprint 2013)
- Rendezvous in Veracruz (1972, reprint 2012)
- Danger, High Explosives! (1972, ebook 2013)
- Flee from the Past (1975, reprint 1998, reprint 2012)
- A Settling of Accounts (1976, reprint 2013)
- Escape from Paris (1982, reprint 2013)
- The Rich Die Young (1983, reprint 2001)
- Death by Surprise (1983, reprint 2013)
- Castle Rock (1983, reprint 2014)
- Skulduggery (1984, reprint 2012)
- The Devereaux Legacy (1986, reprint 2013)
- Brave Hearts (1987, reprint 2013)
- Crimes of the Heart (1995, edited anthology)
- Crime on her Mind (1999, anthology, ebook 2013)
- Love & Death (2001, edited anthology)
- Letter from Home (2003)
- Secrets and Other Stories of Suspense (2008)
- The Sooner Story, 1890-1980 (1980, with Charles F. Long)
- page 110, Great Women Mystery Writers, 2nd Ed. by Elizabeth Blakesley Lindsay, 2007, publ. Greenwood Press, ISBN 0-313-33428-5
- "Carolyn Hart: News: HarperCollins Publishers". Harpercollins.com. Retrieved 2012-01-30.
- "Sooner Magazine, Winter 2007 - Hart Of the Mystery". Oufoundation.org. Archived from the original on 2012-04-06. Retrieved 2012-01-30.
- Wall, Judith (Winter 2007). "Hart of the Mystery". Sooner Magazine. pp. 9–13.
- "Carolyn Hart". Carolyn Hart. Archived from the original on 2012-02-06. Retrieved 2012-01-30.
- "Carolyn Hart". Carolyn Hart. Retrieved 2012-01-30.
- Mystery Guide Interview with Carolyn Hart Archived February 8, 2007, at the Wayback Machine.
- "Library of Congress's website". Loc.gov. 2004-03-11. Retrieved 2012-01-30.
- Carolyn Hart Carolyn G. Hart [1936-]. "Carolyn Hart". Stopyourekillingme.com. Retrieved 2012-01-30.
- "Carolyn Hart". Carolyn Hart. 2006-04-24. Archived from the original on 2012-02-22. Retrieved 2012-01-30.
- "History". Sisters in Crime. Retrieved July 5, 2014.
- "Carolyn Hart". Carolyn Hart. Archived from the original on 2012-01-12. Retrieved 2012-01-30.