Although Leonard Lewis – the hairdresser known professionally as “Leonard of Mayfair” – trained in Vidal Sassoon’s London salon in Bond Street, their approaches to hair and the people beneath it were irreconcilable. Sassoon treated locks as millinery felt, to be cut and sculpted into “hats”, uniformly imposed. Lewis, who has died aged 78, understood hair as organic, sensuous as fur, and that its owners might need psychological support more than a sharp shearing. “We’d discuss how you felt, what you wanted to be,” he told the style magazine Dazed in 2008. “Then we would achieve it, together. The only way hair works is between two people.”

Lewis could do fashion – in 1966 he cropped, and his colourist Daniel Galvin bleached, the schoolgirl Lesley Hornby, and the resultant photograph, hung in the salon, was enough to start her modelling career as Twiggy. He was an early volunteer to style fashion shoots in studios and locations, which most name hairdressers would not do, since it was unprofitable; in the fashion-wig era, from the mid-1960s, his extravaganzas were the wild best.

But Lewis’s sympathy was more important to celebrities, who embodied their own and others’ fantasies; he was discreet about Tony Curtis’s toupee, patient with Elizabeth Taylor’s hairpiece, calm when Mick and Bianca Jagger ranted in his salon. He unpicked and trimmed Bob Marley’s dreadlocks. If a client was not willing, he did not attempt to persuade. Margaret Thatcher’s advisers brought her in for a cut and “she wouldn’t let me touch a strand … that was how she would keep it”.

It cost him effort to ascend. He was born in west London, the unwanted fourth child of a shady car salesman, John Lewis, and his wife, Amelia, of Shepherd’s Bush. Leonard’s education was minimal and the real flash of inspiration came from a 1952 French film, Coiffure Pour Dames, that he saw at the Curzon, Mayfair (Lewis was obsessed with the area), with the comic Fernandel as a sheep-shearer who remakes himself into a stylist adored by Parisian society.

Lewis worked at auctions with his father, who knew many noted crooks, and as a labourer and barrow-boy, and saved enough to pay for three years of apprenticeship with Rose Evansky of Mount Street, who died last month. Boys of rough background were not usually accepted in Mayfair salons — the pinnacle of the UK trade, of near-Parisian glamour — but Lewis got in, and Evansky’s pioneering blow-drying influenced him. Lewis had a year at Sassoon, then set up a small salon on a bank overdraft in Duke Street in partnership with a fellow Sassoon defector, Raphael Santarossa. His final transition was to his Upper Grosvenor Street salon, The House of Leonard. The name was a bit much. So was the venue.

Lewis’s childhood had been dingy and cramped, and to rent five Georgian floors in Mayfair in his 20s was making it. He avoided the traditional local chandelier and frou-frou decor, aiming instead for the buzz of the new bistro restaurants, like his favourite, San Lorenzo – he was more chef-patron than maître-coiffure, despite his staff retinue. Lewis would listen to a client before starting to cut, then requested silence.

The top floor was opened as a barbershop for clients’ menfolk, Galvin’s radical colour experiments were given another floor, and the in-house chemist reformulated the bright textile dyes of the young Zandra Rhodes to apply to hair. She designed the salon’s gowns. Models – Marie Helvin, Jerry Hall — brought in music people (the Stones, Bowie in his Ziggy Stardust phase), who attracted the film folk (Warren Beatty, Audrey Hepburn, Liza Minnelli, Meryl Streep).

Lewis already had a connection to the movie world, as hairdresser to the women of the Carreras family, which owned the Hammer horror production company, and had worked on the films: “I just loved the theatricality, all the lights.” So he was up for Stanley Kubrick’s 2001: A Space Odyssey (1968) – Lewis offered his wigmaker to knot the ape-suits, and styled them, no different from toupee-shaping — and confected the high-frothed, pastel-tinted 18th-century wigs for Barry Lyndon (1975).

Kubrick didn’t want artifice for A Clockwork Orange (1971), so Lewis hacked its brutal proto-punk spikes on the actors for real. Much of the charm of The Boy Friend (1971) lies in Lewis’s sweet bob for Twiggy. Murder on the Orient Express (1974) was heavily Lewis-bewigged.

Lewis lived large and was a spendthrift: town house, country house, restaurants, clubbing. He had little financial acumen, was slow to open salons he could not personally supervise and did not see the future in the name-brand products that began to dominate rivals’ businesses.

In 1986 he collapsed in a Park Lane hotel – Mayfair, of course – and had successful surgery for a brain tumour. There followed alcoholism, bulimia and epilepsy. He was bankrupted, and he survived on income support in the home of his much older sister, until old colleagues, former trainees, and clients set up a trust to fund his nursing-home care. He kept his scissors, and a few friends, including Jack Nicholson, visited for a trim.

His first marriage, to the model Ricci Wade, ended in 1977; in 1980 he was briefly married to Petra Arzberger, who encouraged him to open branches in New York and Dubai.