She has received nine nominations for the Academy Award for Best Costume Design and has won four times for Barry Lyndon (1975), Chariots of Fire (1981), Marie Antoinette (2006), and The Grand Budapest Hotel (2014).

She created an instantly recognizable character's wardrobe that perfectly captures the film's discourse on class, money, and power through provoking aesthetics, which has since become an enduring inspiration for fashion icons and designers.

During an extensive preproduction period, she and Swedish costume designer Ulla-Britt Söderlund examined original 18th-century attire at London's Victoria and Albert Museum and copied patterns from the collection to produce authentic-looking film garments.

[2] Then film director George Lucas approached her to design costumes for his space opera Star Wars (1977), an offer she eventually turned down and later considered the biggest missed opportunity of her career.

She superbly interpreted the 1920s English tweeds, blazers, and college garb to the extent of inspiring 1980s fashion trends; such great success led to an offer for Canonero to create a clothing line for men's-wear manufacturer Norman Hilton, for which she received a special Coty Award.

[2] Canonero’s next major film was Sydney Pollack's Out of Africa (1985), based on Danish author Karen Blixen's autobiographical memoir of the same name about her decade-long experiences in colonial Kenya starting just before the outbreak of World War I. Canonero faced a formidable challenge when tasked in a strict three-month term to research, design, and produce hundreds of costumes appropriate for a vast ensemble of characters that includes African natives, white hunters, and European nobility.

It took her on an intense journey everywhere, from the New York Public Library to the various museums and costume houses across England and Italy, and from the Blixen’s home in Denmark to Africa, where she met anthropologist Richard Leakey, who consulted her on less known aspects of African fashion in the 1910s, especially those regarding the ingenious groups.