Vidal Sassoon, the British-born hair-care magnate who built a global enterprise of salons and hair products and helped liberate women from time-consuming beauty parlor coiffures by popularizing a wash-and-go approach to hairstyling, died May 9 at his home in Los Angeles. He was 84.

Los Angeles police spokesman Bruce Borihanh said officers were called to Mr. Sassoon’s Richard Neutra-designed home in the Bel Air neighborhood and determined his death was from “natural causes.” Mr. Sassoon was diagnosed with leukemia in 2010, according to a British media report.

Trim and dashing, with a baby face and cultured manner that belied his Cockney upbringing in a Jewish orphanage in London, Mr. Sassoon became an international sensation in the 1960s with his vast network of salons and styling schools.

Mr. Sassoon, long a vivacious fixture on social circuits in New York, Los Angeles, Paris and London, gained instant household recognition by appearing in television commercials for his shampoos and sprays. His tagline: “If you don’t look good, we don’t look good.”

Starting in the 1970s, he shrewdly linked his products to the burgeoning general interest in healthy lifestyles. With his then-wife Beverly and former Vogue editor Camille Duhe, Mr. Sassoon co-wrote “A Year of Beauty and Health,” which became a bestseller in 1975. Images of top models and actresses displaying his simple, luminous hair artistry were featured in a career retrospective at New York’s Fashion Institute of Technology in 1993.

“Sassoon is in the small coterie of creative individuals who have defined what it means to be modern,” Richard Martin, the curator of the Metropolitan Museum of Art’s Costume Institute, said at the time.

Clean geometric lines had been Mr. Sassoon’s driving motivation since opening his first salon in London in 1954. At the time, most women were resigned to going to bed at night with rollers in their hair. His approach grew into a direct assault on the beehive style and other formidable towers of hair seemingly shellacked with hairspray.

In 1957, he launched a fruitful collaboration with British clothes designer Mary Quant, the widely acknowledged “mother of the miniskirt.” In the bob style he perfected for Quant — who wanted her models’ necks and shoulders bare — Mr. Sassoon crafted a look that was tight at the nape but allowed the hair to fall in a flirty, bohemian cascade.

The “Sassoon bob” became the rage of Swinging London and one of the most enduring hairstyles of the last half-century. Variations on the bob included the popular “five-point” cut first modelled in 1963 by Grace Coddington.

Subsequent hairstyles he promoted included an asymmetrical, peek-a-boo bob and a short, closely curled look called the “greek goddess.”

Mr. Sassoon’s services were requested by prominent high-fashion models, including the sisters Suzy Parker and Dorian Leigh, socialites such as Lee Radziwill, and movie stars such as Nancy Kwan and Mia Farrow, for whom he designed a pixie-like hairstyle for her career-making performance in Roman Polanski’s modern gothic horror film “Rosemary’s Baby” (1968).

By that time, Mr. Sassoon focused on aggressively expanding his business empire. He recognized that the real profit center was hair products: shampoos, protein mixtures, brushes and hand-held blow dryers.

The Sassoon brand reached sales of more than $100 million annually when he sold the line to Richardson-Vicks in 1983. That part of the business was later acquired by Procter & Gamble, where Mr. Sassoon became a consultant and celebrity spokesman for his brand.

Vidal Sassoon was born Jan. 17, 1928, in London. His family’s forebears were Jewish, from Ukraine on his mother’s side and Greece on his father’s.

His father, a carpet salesman, abandoned the family for another woman and left his wife and two young sons in poverty. In his memoir “Vidal,” Mr. Sassoon referred to his father as a “con artist who had the gift of the gab. . . . I was later told my father spoke seven languages and had sex in all of them.”

After his father left, Mr. Sassoon spent seven years in an orphanage. He was a self-described “semi-literate” Cockney with little ambition for schooling. He quit formal education at 14 and found an apprenticeship with a London hairdresser. It was drudgery, shampooing hair, sweeping the floor and cleaning combs.

During World War II, Mr. Sassoon became involved in vigilante gangs of tough young London Jews that beat up supporters of the British Union of Fascists. Mr. Sassoon, coarse and sinewy, learned to throw a good punch.

One day at the salon, a worried customer noticed Mr. Sassoon had been roughed up. “Good, God, Vidal, what happened to your face,” she asked. He replied: “Oh, nothing, madam, just tripped over a hairpin.”

In 1948, at age 20, he volunteered for service in the Israeli defense forces and participated in the Arab-Israeli War.

The experience in Israel was formative. “In Britain, I had always felt like a second-class citizen,” he told the Boston Globe in 1989. “In Israel, I had found my dignity. I translated that dignity into my career. I had been a shampoo boy. . . . I decided I could be better, do better. I went to night school. I took courses in elocution.”

Working at salons at night, he listened to classical composers and modern jazz. He studied the Bauhaus modern design movement, from which he took its emphasis on clean lines and adapted it toward hairstyling.

The relationship with Quant led Vogue and other trend-setting fashion magazines to take notice of Mr. Sassoon. By the late 1960s, he was making inroads in North America with his salons and training academies.

Mr. Sassoon’s role in guiding the company diminished in the 1970s, but he remained an indefatigable promoter of all things Sassoon on radio and television. He started a foundation that awarded scholarships to underprivileged African Americans who aspire to a career in hairstyling. He also supported a center for the study of anti-Semitism at the Hebrew University in Jerusalem. He received a knighthood from Queen Elizabeth II in 2009.

Mr. Sassoon was thrice divorced. His first wife, Elaine Wood, had been a receptionist at his salon in London. With his second wife, Beverly Adams, he had three children — Catya, Elan and Eden — and adopted a son, David. Mr. Sassoon told the London Daily Mail that his third wife, Jeanette Hartford, a horse trainer, “gave me up for horses.”

Survivors include his fourth wife, the former Rhonda Carper Holbrook, whom he married in 1992. His daughter Catya died of a drug overdose in 2002.

For some women, a marriage to one of the world’s foremost hairstylists might sound like almost unimaginable fun. Rhonda Sassoon once told the New York Times she never let her husband go near her with his tools of the trade. “He cut my hair once and chased me around for most of the weekend with a pair of scissors, saying, ‘Stop. Stop,’ ” she said. “He kept wanting to fix it.”