The actress, who played Lydia in Heroes before being killed off in a recent episode, has reportedly landed the role of Janice Herveaux.
Her character, Janice, is the sister of Joe Manganiello's werewolf Alcide, who is rumoured to become romantically involved with Anna Pacuin's Sookie Stackhouse.
Janice is described as a "tough-as-nails biker chick" who is fiercely overprotective of her younger brother.
According to Olivieri's rep, she originally auditioned for the role of Alcide's ex-girlfriend Debbie Pelt, a part which was later won by Brit Morgan.
> 'True Blood' romance was 'unexpected'