Luisa Casati's only grandchild, Lady Moorea Hastings, was the wife of politician and diarist Woodrow Wyatt from 1957 to 1966, and later married the adman Brinsley Black, named as one of the best-dressed Englishmen in the inaugural issue of Men in Vogue in 1965.

[citation needed] In 1910, Casati took up residence at the Palazzo Venier dei Leoni, on Grand Canal in Venice, owning it until circa 1924.

Today it is the Peggy Guggenheim Collection, a modern art museum on the Grand Canal in the Dorsoduro sestiere of Venice, Italy.

Her time on the Italian island, tolerant home to a wide collection of artists, gay men, and lesbians in exile, was described by British author Compton Mackenzie in his diaries.

Numerous portraits were painted and sculpted by artists as various as Giovanni Boldini, Paolo Troubetzkoy, Adolph de Meyer,[14] Romaine Brooks (with whom she had an affair), Kees van Dongen, and Man Ray;[15][16] many of them she paid for, as a wish to "commission her own immortality".

Augustus John's portrait of her is one of the most popular paintings at the Art Gallery of Ontario; Jack Kerouac wrote poems about it and Robert Fulford was impressed by it as a schoolboy.

The inscription on the tombstone, which misspells her "Louisa" rather than "Luisa", is inscribed with the quote, "Age cannot wither her, nor custom stale her infinite variety", from Shakespeare's Antony and Cleopatra.

Casati served as inspiration for another of Galliano's ensembles created for his autumn/winter 2007/2008 Bal des Artistes haute couture collection for Dior.

Casati is also the namesake of the Marchesa fashion house started by British designers Georgina Chapman and Keren Craig.

[23] In 2021, singer, songwriter and actress Lady Gaga referenced Casati in one of her pictures of the photoshoot from the December British Vogue/November Vogue Italia issues.

In 2021, Canadian author T. H. Cini wrote a fictional novelette based on meeting the Marchesa (Luisa Casati) in the narrators’ dreams.

The Marchesa and the Palazzo Vernier dei Leoni appear in The Glassmaker, a novel by Tracy Chevalier published in September 2024.