Kristen Bell in August this year.

Kristen Bell in August this year. Photo: Getty

Actress Kristen Bell and her fiance, Dax Shepard, have babies on the brain.

Bell's representative, Marcel Pariseau, says the couple are expecting their first child next year.

Shepard, 37, appears on the US TV drama Parenthood. Bell, 32, has a role on House of Lies, also starring Don Cheadle. She also narrates Gossip Girl as the show's title character.

Shepard and Bell co-starred in the film Hit & Run this year which Shepard also wrote and directed.

Earlier this year, Bell joked that she and Shepard had no problem working together because they are "severely co-dependent".

The couple, both originally from Michigan, started dating in 2007. They have been engaged for about three years.

AP