Isabelle Demarly, also known as Isaly, is a children's book illustrator.

She obtained a baccalaureate in Applied Arts, then decided to continue her studies by attending an art school. She graduated from the Émile Cohl school in 2010.

"Mademoiselle Sel" (2012) is her first book published by Des ronds dans l'O. Four months later, "La petite vieille du vendredi" was released, also by Des ronds dans l'O.