Stella made her cinematic debut at the age of 16 in 2001 in L'ultimo bacio. The film was a success in Italy, and was nominated for multiple 2001 David di Donatello awards, including Best Film.
L'ultimo bacio was released internationally, with the title The Last Kiss for English-speaking audiences. Reviews of Stella's performance as Francesca, a beautiful teenager who seduces a man in a committed relationship, were generally positive. One American reviewer compared her to "a young Reese Witherspoon", while another described her portrayal in greater depth: In an American movie, Francesca would be presented as a virgin with a Britney Spears-like come-on or trivialized as a mindless bimbo. In "The Last Kiss," she's presented without judgment as a normal, sexually active girl with a lot to learn about men. It's a balanced and sympathetic portrait.
Stella proceeded to build a career as an actress in Italian films, including 2002's Amnèsia, which was directed by past Academy Award-winner Gabriele Salvatores. Her film career has also included a small role in the 2004 Hollywood movie Ocean's Twelve. She studied English for her role in the 2009 Rob Marshall film Nine.
Stella made her theatrical debut in 2002 in Aggiungi un posto a tavola, and briefly returned to the stage in 2006 in Romeo e Guilietta. Stella has also played lead roles in various Italian television projects, including the miniseries Le ragazze di San Frediano and Piper.
