It's the biggest reveal of 2015 for sure ... Bruce Jenner as a woman, and the pic is dramatic.

The name's now Caitlyn. She posed for the cover of Vanity Fair's July issue and it was shot by famed celeb photographer Annie Leibovitz.

It's interesting the name is spelled with a C and not a K ... possibly a break from the Kardashian Klan.

In the Diane Sawyer interview Bruce made it clear he was saying farewell to his male persona. This pic is a full reveal of the transformation.

Caitlyn just opened a Twitter account, saying, "I'm so happy after such a long struggle to be living my true self. Welcome to the world Caitlyn. Can't wait for you to get to know her/me."