Sasha Pieterse (born February 17, 1996) is a South African-born American actress and singer-songwriter. She landed her first major role at the age of thirteen, as Alison DiLaurentis on ABC Family's series Pretty Little Liars, becoming the youngest cast member. Upon the success of the series, Pieterse earned a supporting role as Amy Loubalu in the 2011 Disney Channel film Geek Charming. In 2013, she starred in the teen comedy film G.B.F. which became a commercial and critical success.