[1][3] He attended the École des hautes études commerciales in Paris between 1911 and 1913,[1] first studying political science but graduating with a business degree.

[1] In the following years, Lucien Lelong was recognised as an up-and-coming fashion house, alongside those of Jean Patou and Edward Molyneux.

[3] In 1924, Lelong moved his fashion house to Avenue Matignon [fr] in Paris' 8th arrondissment and began creating perfume.

[2]: 80  Robes d'Edition filled a niche in between manufactured and bespoke clothing; designs were made in five sizes with alterations being able to be added to the garment's cost.

[2]: 77–78  In 1925, Lelong was offered a study trip to the US by the French Ministries of Fine Arts, Public Instruction, and Labour.

[2]: 78  He opened a perfume branch in Chicago in 1928,[1] and by July 1929 had leased a New York office at 657 Fifth Avenue to serve as an East Coast headquarters and manage Lelong's sales to US department stores.

[2]: 79 Lelong traveled to America in October 1935 on a study trip commissioned by Pierre Laval, then Minister for Foreign Affairs, to report on working conditions in the American clothing industry.

[2]: 100 The Second World War had "an immediate effect on Paris fashion", and many houses closed, including Mainbocher, Charles James, and Schiaparelli.

[7]: 111  Ten days after being mobilised, Lelong was demobilised and sent back to Paris; American journalist Kathleen Cannell suggested that this was on the orders of the French government.

[7]: 111 On 12 September, Lelong called a committee meeting where the potential for resuming work was discussed; one of the most important dilemmas was how to keep the sector's 25,000 workers employed and avoid redundancies.

[7]: 112  Couturiers had to keep paying taxes, rent and wages but were unable to recover credit extended to their private customers which amounted to a value of 100 million francs.

[7]: 112  In a meeting of the Chamber Syndicale on 6 October, Lelong said that "opening one's house can be considered an act of national duty".

[7]: 115  The Chamber Syndicale in April gave Lelong full responsibility for the industry during the war and he was appointed to a post in the Ministry of Information as head of a unit in charge of developing French luxury business during wartime.

[3] In August 1940, Lelong presented plans to the Chambre Syndicale supporting widespread industry reorganisation along corporatist lines in order to work within the German occupation decrees.

[7]: 120–121  The law of 16 August 1940 created comités d'organisation which would oversee production and resource distribution,[9] effectively moving occupied France to a state-controlled economy.

[7]: 122 Lelong persuaded the Nazis to keep the industry in Paris,[10] arguing that any attempt at relocation would kill the industry due to its fragile supply chains; his fashion house was one of those allowed to stay open during the occupation and largely catered to the wives and daughters of Nazi officers who were some of the only people allowed to buy haute couture garments.

[3] In January 1942, Lelong said that, during the war, "our single preoccupation was to keep Paris Couture alive despite the innumerable difficulties" and that his work with both the French and occupation governments was "inspired by our only concern of defending the profession's interests.

[13] The dolls were 27 inches (69 cm) high wire figures with plaster faces by Joan Rebull [es], a Catalan sculptor.

[2]: 83 Lelong's health deteriorated in 1947 and caused the end of his career;[3] he retired from couture in August 1948, leaving his fall collection unfinished,[15] and only continued his perfume business.