The pretty blonde couldn't believe it when her mother Frances Fisher called and told her the news, and admits the honour took a while to sink in.
She says, "My mum called and said, 'They want you to be Miss Golden Globe' and I was like, 'Are you serious?' And then I screamed... It was amazing.
"They just choose you. They go through a list of girls... They told me that I beat out a lot of girls."
As Miss Golden Globe, Eastwood will be tasked with handing trophies to prize winners and then ushering them backstage at the big event in January (13). Her predecessor is Andie MacDowell's daughter Rainey Qualley, who held the title for this year's (12) Globes.
Eastwood admits she's nervous about "falling over" onstage - but whatever happens on the night, she knows she has made her dad proud.
She tells U.S. news show Access Hollywood Live, "He's excited. He's really supportive of me doing this."
Andie Macdowell's daughter Rainey Qualley has been chosen as Miss Golden Globe 2012. The role requires her to help winners off-stage at the event on 15 December (12). Previous Miss Golden Globes have included Melanie Griffith, Laura Dern and Rumer Willis.
Qualley makes her debut as MacDowell's eldest daughter Maddie in the forthcoming film, about a man who struggles with bipolar disorder and the effect it has on his family.
But MacDowell reveals their first shoot together was far from easy, admitting she felt uncomfortable when Qualley acted out her intense scenes.
She tells the Daily Mail's Weekend magazine, "In (Mighty Fine), I'm married to a man who's bipolar and takes it out on our daughter, and I don't protect her. The role was very demanding, very abusive. What my daughter went through makes me cringe."