Some ways to contact celebrities include using their verified social media platforms such as Facebook, Twitter or Instagram or reaching out to them through their official websites. It is likely, however, that these channels are managed by the celebrities' publicists, and messages may not always get to the celebrities themselves.
A celebrity's fan mail address may be found on her official website; this allows fans to write to the celebrity, though the letter may never be opened. A more assured way to contact a celebrity is through her agent or manager; agents typically handle requests for bookings for endorsements and appearances.
Some websites claim to provide reliable celebrity contact information at a fee. These online services are not reliable and could be scams.