Born in Washington, D.C. to a British father and an American mother (Herbert Frederick King and Louise Ruding King), Florence King grew up in the District with her parents, her maternal grandmother and her grandmother's maid. Each of these people influenced her development as a person. In particular, her grandmother required high standards of behavior from Florence, referring to the family as descendants of Virginia's colonial elite. In many of her writings, King often refers to the comical contradictions between the material reality of her upbringing (lower middle class) and the snobbish behavior of her grandmother.

In 1957, King received her B.A. in history from American University in Washington D.C., where she was inducted into Phi Alpha Theta. She also attended the University of Mississippi as a graduate student, but did not complete her M.A. degree after the traumatic loss of her former girlfriend in a car crash.

King had several occupations before she began writing as a career. In the mid-1950s, she was a history teacher in Suitland, Maryland. Later in the decade, she was a file clerk at the National Association of Realtors. From 1964 to 1967, King was a feature writer for the Raleigh News and Observer. While at the newspaper, Miss King received the North Carolina Press Woman Award for reporting.

The majority of King’s works under her own name have been non-fiction essays. She also wrote a historical romance novel, Barbarian Princess, under the pseudonym Laura Buchanan. King has also admitted to having written numerous pornographic stories, pulp paperback books and erotica under various pseudonyms. She gained national attention with her column "The Misanthrope's Corner" in National Review, a conservative magazine of political and social commentary. In addition, she wrote numerous articles for The American Enterprise magazine.

King's first book published under her own name was 1975's Southern Ladies and Gentlemen. The work provides a humorous guide to the South for "Yankees". Her most popular book, Confessions of a Failed Southern Lady (1985), is a semi-autobiographical work focusing on, among other things, her grandmother's, mother's, and father's construct of "a lady."

In Confessions, King says she had relationships with both men and women during college: one woman she fell in love with was killed in a car crash. This relationship was detailed in Confessions of a Failed Southern Lady. She jokingly describes herself as a "conservative lesbian feminist" and has been referred to as the "World's Funniest Bi-Sexual-Republican."

King has later expressed regret at revealing her bisexuality, saying she did not want to be part of the "gay liberation movement" and embracing the concepts of "spinsterhood" and "the old maid."

In 1995, King publicly accused the writer Molly Ivins of plagiarizing her work. Ivins publicly acknowledged and apologized for her error.

King, who now lives in Fredericksburg, Virginia, retired in 2002 (at which time National Review published an anthology of her columns entitled STET, Damnit!), but resumed writing a monthly column for National Review in 2006, titled in 2007 "The Bent Pin". . A selection of her book reviews and articles was released under the title Deja Reviews: Florence King All Over Again in October 2006.

• King on stress: "The American way of stress is comparable to Freud's 'beloved symptom', his name for the cherished neurosis that a patient cultivates like the rarest of orchids and does not want to be cured of. Stress makes Americans feel busy, important, and in demand, and simultaneously deprived, ignored, and victimized. Stress makes them feel interesting and complex instead of boring and simple, and carries an assumption of sensitivity not unlike the Old World assumption that aristocrats were high-strung. In short, stress has become a status symbol." (from "The Misanthrope's Corner", May 2001)

• King on the American attention span: "The American attention span always has gotten a lot of attention. The first to note our easy distractibility was Alexis de Tocqueville. His findings were echoed by Frederick Jackson Turner, but being an American, Turner used the more tactful and romantic 'restlessness.'

"...Our distractibility is also the inevitable residue of our undisciplined feelings. The American proclivity for leaving our emotional lights on has drained the battery of our attention span dry. The human spirit can take only so much of 24-hour coverage, memorial services, ribbons, teddy bears, crisis counseling, and moments of silence. We pay such obsessive attention to disasters and tragedies that we end up seeking respite in forgetfulness. (Quick, name one Teheran hostage.)

"Welcome to America, the Flea Circus. We now have a new disease, Attention Deficit Disorder, and like all democratic diseases, it does not discriminate. The good news is that by the time we run the gauntlet of ADD resources, clinics, programs, workshops, seminars, CBS Specials, and Sally Struthers promos, no one will remember what it is." (from "The Misanthrope's Corner", June 1995)

• King summed up her writing efforts in a May 2002 "Misanthrope's Corner": "Being a writer has made me a lifelong practitioner of no-holds-barred insight, driven by an irresistible impulse to shovel through mountains of received bull to get to the bottom of things."

• As an example of the manners taught to her by her grandmother, she wrote: "No matter which sex I went to bed with, I never smoked on the street." (from Confessions of a Failed Southern Lady, 1985)