Henri Marie Raymond de Toulouse-Lautrec-Monfa was the firstborn child of Alphonse Charles Comte de Toulouse-Lautrec-Monfa (1838–1913) and his wife Adèle Zoë Tapié de Celeyran (1841–1930). The last part of his name means he was a member of an aristocratic family (descendants of the Counts of Toulouse and Odet de Foix, Vicomte de Lautrec and the Viscounts of Montfa, a village and commune of the Tarn department of southern France, close to the cities of Castres and Toulouse). If Henri had outlived his father, he would have been accorded the family title of Comte de Toulouse-Lautrec.
Toulouse-Lautrec's parents, the Comte and Comtesse, were first cousins (his grandmothers were sisters), and his congenital health conditions were attributed to a family history of inbreeding.
At the age of eight, Toulouse-Lautrec went to live with his mother in Paris (his parents separated), where he drew sketches and caricatures in his exercise workbooks. A friend of his father, René Princeteau, sometimes visited to give informal lessons.
At the age of 13, Toulouse-Lautrec fractured his right femur, and at 14, he fractured his left femur. His legs ceased to grow, so that as an adult he was extremely short (1.42 m or 4 ft 8 in). He developed an adult-sized torso while retaining his child-sized legs. Additionally, he is reported to have had hypertrophied genitals.
Unable to participate in activities enjoyed by boys his age, Toulouse-Lautrec immersed himself in art. He became a prominent Post-Impressionist painter, art nouveau illustrator, and lithographer, and, through his works, recorded many details of the late-19th-century bohemian lifestyle in Paris. In addition to growing alcoholism, Toulouse-Lautrec was fascinated by the lifestyle of the "urban underclass" and prostitutes, incorporating their characters into his paintings. He created about a hundred drawings and fifty paintings inspired by the life of these women.
When the Moulin Rouge cabaret opened in 1889, Toulouse-Lautrec was commissioned to produce a series of posters. Other artists looked down on the work, but he ignored them. The cabaret reserved a seat for him and displayed his paintings.
His family members were Anglophiles, he traveled to London, where he was commissioned by the J. & E. Bella company to make a poster advertising their paper confetti and the bicycle advert La Chaîne Simpson. While in London, he met and befriended Oscar Wilde and became a vocal supporter of him when Wilde faced imprisonment in Britain.
On 9 September 1901, at the age of 36, he died from complications due to alcoholism and syphilis at his mother's estate, Château Malromé, in Saint-André-du-Bois. He is buried in Cimetière de Verdelais, Gironde.
The Earthquake cocktail (Tremblement de Terre) is attributed to Toulouse-Lautrec: a potent mixture containing half absinthe and half cognac in a wine goblet. A collection of his favorite recipes – some original, some adapted – was posthumously published by his friend and dealer Maurice Joyant as L'Art de la Cuisine. The book was republished in English translation in 1966 as The Art of Cuisine.