According to Vogue UK, Jarrar will replace Alber Elbaz, who left the luxury fashion label in October.
The Paris designer will make her debut for Lanvin with a collection for spring/summer 2017. Its previous creative director Alber Elbaz left in October last year.
"Her timeless style is in keeping with the style and values of our company," Lanvin chief executive officer Michèle Huiban said in a statement.
"Her talent, her high standards and her mastery of cuts and fabrics will bring a breath of freshness and modernity into the house, while respecting its soul as the oldest Paris couture house, a symbol of French elegance."
After 15 years working at fashion houses such as Jean-Paul Gaultier, Balenciaga and Christian Lacroix, Jarrar started her own couture label in 2010.