'Gossip Girl' and 'Veronica Mars' star Kristen Bell is to marry her actor boyfriend Dax Shepard.

People.com reports that Bell wore an engagement ring to the Grammy Awards on Sunday night.

The actress' spokesman told People: "Yes, they are engaged. Over the holidays."

Bell, who narrates 'Gossip Girl' and also starred in 'Heroes', has been dating 'My Name is Earl' star Shepard for a number of years.

They star together in the new romantic comedy 'When in Rome'.