Judith Krantz (née Tarcher; January 9, 1928 – June 22, 2019) was an American magazine writer, fashion editor, and novelist. Her first novel Scruples (1978) was a New York Times best-seller and was translated into 50 languages. Scruples, which describes the glamorous and affluent world of high fashion in Beverly Hills, California, helped define a new sub-genre of the romance novel — the bonkbuster or "sex-and-shopping" novel. She also became a "celebrity author" through her extensive touring and promotion. Her later books included Princess Daisy (1980), Mistral's Daughter (1982) Till We Meet Again (1988), Dazzle (1990), and Spring Collection (1996). Her autobiography, Sex and Shopping: The Confessions of a Nice Jewish Girl, was published in 2000.

Judith Bluma-Gittel Tarcher was born on January 9, 1928, in New York City, the daughter of Mary (Braeger), a Lithuanian-born attorney, and Jack D. Tarcher, an advertising executive. Her family was Jewish. The "youngest, smartest, and shortest girl" in her year, she graduated from the Birch Wathen School at age 16. Krantz then enrolled at Wellesley College.

Krantz told The Boston Globe in 1982 that she attended Wellesley with three goals: to date, to read every novel in the library, and to graduate. "Torchy", as her dormmates named her, held the dorm dating record as the only one to have 13 consecutive dates with 13 different men. Her grades were not as impressive as her extracurricular activities. Krantz earned one A-plus in English, but had a B− average in her major and C average in everything else. Krantz had the opportunity to improve her marks when she took a short-story class during her sophomore year. Although the professor enjoyed her writing, he refused to give her an A because she had poor spelling, and he thought the B would teach her a lesson. Krantz claims to have learned the lesson well—she did not write fiction again for 31 years.

After graduating from Wellesley in 1948, Krantz moved to Paris, where she worked in fashion public relations. She enjoyed attending elegant parties, borrowing couture gowns, and meeting prominent people such as Marlene Dietrich, Orson Welles and Hubert de Givenchy.

The following year, Krantz returned to New York City, where began a career in magazine journalism. She worked in the fiction department at Good Housekeeping before being promoted to fashion editor and having the opportunity to write several articles for the magazine.

In 1953 Krantz attended a Fourth of July party hosted by her high school friend, Barbara Walters. There she met the future film and television producer Steve Krantz. The two were married the following year, on February 19, 1954. Three years later, she gave birth to their first son, and she gave up her full-time job, choosing instead to write part-time from home. She wrote many freelance articles for Maclean's, McCall's, Ladies' Home Journal, and Cosmopolitan. Her best-known article was "The Myth of the Multiple Orgasm", which was published in Cosmopolitan. Her magazine career gave Krantz an opportunity to interview many prominent women.

In 1976, Krantz's husband decided to take flying lessons. Despite Krantz having a fear of flying, she joined the flying lessons with him, after which her fears were subdued. Subsequently, she wrote fiction for the first time since college. Although her husband had been insisting for years that she was a natural storyteller, Krantz believed that she was writing the book simply to prove to him that she was not able to write good fiction.

She completed her first novel, Scruples, nine months later. The year it was published, 1978, Krantz turned 50. The books were not copyrighted under her own name but by Steve Krantz Productions. Scruples reached the number one spot on The New York Times bestseller list. There were two sequels: Scruples Two (1992) and Lovers (1994).