Founded by Robert Redford, the Sundance Film Festival showcases independent films along with a competition section.
Movies in competition this year include The End of Love starring Amanda Seyfried and Michael Cera, Nobody Walks with John Krasinski and Olivia Thirlby, and The Surrogate featuring William H Macy, John Hawkes and Helen Hunt.
When asked what she's doing to prepare for her hosting gig, Posey joked to USA Today: "I've been cutting up a lot of vegetables. I'm making a lot of hummus and a great spinach-yogurt dip. I just hope everyone is happy with it."
Posey, whose new film Price Check premiered at Sundance, also quipped that it was due to her history of acting in independent films that she got the hosting job.
She said: "Well, you know I am the queen of independent films. So it only seems right that I am hosting the ceremony."
Last year, Redford announced that London will get its own Sundance Film Festival in April called Sundance London.
Watch a scene from Price Check below: