Ros Fisher is one of the background characters in Prisoner Cell Block H. She is described as the sister of Tammy Fisher, often seen arm in arm with her in the episodes leading up to Tammy's death in the Ruth Ballinger siege. After Tammy's death, there is a shot of her alone in the rec room after the others have left.she is one of the backgrounders who appear in the montage in the final episode. She appears throughout most of the series and is never credited. She is of the few people who witnessed the down fall of Joan Ferguson

She was played by Marinia Jonathan