Hunziker was born in Sorengo (Lugano), in the southern, Italian speaking part of Switzerland. Her mother Ineke is Dutch; her father Rudolf, who died of a heart attack in the fall of 2001, was a German speaking Swiss national. He was a painter, but worked as a hotel manager. In 1983, the family moved to Ostermundigen, a suburb of Berne in the German speaking part of Switzerland which is also hometown to Swiss Hollywood star and legendary first Bond girl Ursula Andress. In Ostermundigen Hunziker attended elementary school. After her parents' separation, Hunziker's mother moved to Zuchwil/Solothurn. This caused a crisis in Hunziker's life. In 1993, when Hunziker was 16 years old, she moved to Bologna with her mother. Wanting to become an interpreter, she studied Italian, French, German, English and Dutch at a local college. After moving to Milan with her mother, she decided to become a fashion model and was hired by Riccardo Gay, a renowned agent. Although considered to be both too heavy and short, at 17 she posed for well-known labels such as Armani, Rocco Barocco, La Perla, Colmar, Fuerte Ventura, Lovable and Swish.

Being Eros Ramazzotti's fiance, she was discovered by a TV-producer. In 1996, she co-hosted the RAI Uno-show I cervelloni with Paolo Bonolis. In summer she presented the prime time comedy show Paperissima Sprint (Canale 5) with Gabibbo. Because of her popularity she hosted the afternoon show Colpo di Fulmine (Italia 1) in 1997. At the same time she wanted to extend her artistic abilities. Therefore she attended the professional academy M.A.S. in Milan with her choreographer Susanna Beltrami.