Francesco Risso will become creative director of the label.
The designer had most recently been freelancing after running his own label and working at Cerruti and Jack Wills.
Fullerton plans to focus on the mascara category.
The company has revealed plans for a drastic reorganization that will result in the cutting of almost 30 percent of its workforce to return to operating profitability in 2018.
The executive is bringing 52-year-old Kérastase back to its roots in the digital age.