Modeling Blondeau began modelling at the age of 4, walking on the runway for French designer
Jean Paul Gaultier and later for famous designers like
Dolce & Gabbana, babylos, and
L'Oréal. In 2006, the supplement of French fashion magazine
Vogue,
Vogue Enfants, designated her "the most beautiful little girl in the world". She had her first photoshoot at seven years old with photographer and would become the photographer’s
muse. Brubaker cast her in multiple campaigns for
Hugo Boss and other children fashion campaigns. She represented the French
modelling agency success kids between 2005 and 2016. When she was 10, Blondeau was involved in a controversy over the sexualisation of children in advertising and the media when she appeared in adult clothing and make-up for the
Vogue Paris supplement
Vogue Enfants. At age 13, she appeared on the cover of the magazine
Jalouse. In 2015, she signed with
IMG Models. In 2017, she became a brand ambassador for
L'Oreal Paris. In December 2018, Thylane placed first in the annual "Independent Critics List of the 100 Most Beautiful Faces of 2018". It was her fifth consecutive appearance on the prestigious global list, having been 84th in 2014, 28th in 2015, fifth in 2016, second in 2017, and fourth in 2019.
Acting Blondeau made her acting debut playing the role of Gabriele in the film
Belle & Sebastian: The Adventure Continues (2015). ==Personal life==