He was born in Gibraltar to a Gibraltarian father, Juan Galliano, and a Spanish mother, Anita, and has two sisters.Galliano's father was a plumber. His family moved to England in pursuit of work when Galliano was six, and settled in Streatham, South London, before moving to Dulwich and later to Brockley. He was raised in a strict Roman Catholicfamily. Galliano, who was shy and diffident, often spoke of his struggle to fit in. Recalling his early days, he once admitted: "I don't think people here understood where I was coming from." His mother, a flamenco teacher, would dress him in his "smartest" outfit even for a trip to the local shops. This, combined with his creative sensibilities, saw him frequently bullied at the London boys' grammar school he attended.
After attending St. Anthony's School and Wilson's Grammar School in London, Galliano went on to study at Saint Martin's School of Art, from which he graduated in 1988 with a first class honours degree in Fashion Design. His first collection was inspired by the French Revolution and entitled Les Incroyables, with a music soundtrack mixed by DJ Jeremy Healy. The collection received positive reviews and was bought in its entirety for resale in the London fashion boutique Browns. Galliano then started his own fashion label alongside long-term collaborators Amanda Harlech, at that time stylist with Harpers and Queen, and Stephen Jones, a milliner.
On the back of this success, Galliano rented studio space in London, but his talent was not matched by a head for business. Moreover, he would take his enjoyment of London's nightlife to extremes. Initially, financial backing came from Johan Brun, and when this agreement came to an end, Danish entrepreneur Peder Bertelsen, owner of firm Aguecheek, who were also backing Katharine Hamnett at the time, took over. This agreement ended in 1988 and Galliano sought the backing of German agent Faycal Amor (owner and designer of fashion label Plein Sud) who directed him to set up his base in Paris. Galliano relocated to Paris in search of financial backing and a strong client base. His first show was in 1989 as part of Paris Fashion Week. By 1990, he was bankrupt and, after his own London-based label failed to re-ignite his fortunes, he moved to Paris.
Media fashion celebrity Susannah Constantine has worked for Galliano, and he has also aided the future success of other designers including shoe designer Patrick Cox. In 1991, he collaborated with Kylie Minogue, designing the costumes for her Let's Get to It Tour.
In 1993, Galliano's financial agreement with Amor ended and he did not have a showing in October, missing the season. With the help of American Vogue editor-in-chief Anna Wintour and André Leon Talley, then European Correspondent at Vanity Fair, Galliano was introduced to Portuguese socialite and fashion patron Sao Schlumberger and financial backers of venture firm Arbela Inc, John Bult and Mark Rice. It was through this partnership that Galliano received the financial backing and high society stamp needed to give him credibility in Paris. This collection was important in the development of Galliano as a fashion house, and is regarded as a 'fashion moment' in high fashion circles.
In July 1995, he was appointed as the designer of Givenchy by Bernard Arnault, owner of luxury goods conglomerate LVMH, thus becoming the first British designer to head a French haute couture house. On 21 January 1996, Galliano presented his first couture show at the helm of Givenchy at the Stade de France. The collection received high praise within the fashion media. Some of Galliano's designs for Givenchy were licensed to Vogue Patterns.
In October 1996, LVMH moved Galliano to Christian Dior, replacing Italian designer Gianfranco Ferré. In 2010, Galliano identified his love of theatre and femininity as central to his creations; he said "my role is to seduce", and credited Standard Oil heiress Millicent Rogers as an influence.