I thought it would be good to compile celebrity self-typings here for reference, and in order to prevent me from posting mostly MBTI-typings in "proper" threads.
If you have twitter and follow many accounts, searching for MBTI-types may provide such typings.
Helena Bonham Carter - considers himself an introvert (according to http://www.celebritytypes.com)
Sean Connery - considers himself an introvert (according to http://www.celebritytypes.com)
John Cleese - considers himself an introvert (according to http://www.celebritytypes.com)
Marina Diamandis (Marina and the Diamonds) - considers herself an introvert (according to http://www.celebritytypes.com)
Diana, Princess of Wales - INFP (MBTI), reputedly
Roger Ebert ENFP (MBTI) (according to his twitter account...I think)
Dakota Fanning ENFJ (her Jungian self-type according to http://www.celebritytypes.com)
Megan Fox - considers herself an introvert (according to http://www.celebritytypes.com)
Lauren Laverne ENFJ (MBTI) (according to her twitter account)
Lykke Li INFJ (MBTI) (according to her twitter account)
Nigella Lawson - ESFP (MBTI) (according to her twitter account)
Jennifer Jason Leigh INFP (according to http://www.celebritytypes.com)
JK Rowling INFJ (MBTI) (according to her book The Silkworm)
Mia Wasikowska - INFP (her Jungian self-type according http://www.celebritytypes.com)
Quite surprised at some of the people who consider themselves introverts.