Rialle is a fictional character in the fantasy novel trilogy The Echorium Sequence by Katherine Roberts and features in all three novels in the trilogy. In Song Quest, Rialle was a young novice singer in the final years of The Echorium whereas in Crystal Mask; the story carries on 20 years later, Rialle lives her life as a partial Singer and mostly works and spends most of her times in the caves surrounding The Echorium on the Isle of Echoes. In Dark Quetzal, Rialle also plays a major part in the storyline and build-up in the novel.