Ferri was born in Milan in 1963 and studied at the Teatro alla Scala until age 15, when she joined the Royal Ballet School. She became a member of the Royal Ballet in 1980 and danced leading roles in The Sleeping Beauty, The Two Pigeons, Swan Lake, and the title roles in Manon and Romeo and Juliet. She originated roles in several Kenneth MacMillan productions and danced Odette in Franco Zeffirelli's Swan Lake in Milan.
Ferri is a permanent guest artist with La Scala (her last performance there is reportedly planned for March 2007) and has also appeared with the Ballet National de Marseille in Roland Petit's Le Diable Amoreux, which he created for her. Ferri has also appeared with many other international companies.
Ferri has been awarded the Prix de Lausanne (1980) and the Olivier Award (1982) and was named a Cavaliere della Repubblica Italiana in 2005.