Teletha "Tessa" Testarossa (テレサ・テスタロッサ, Teresa Tesutarossa?) is a fictional character from the light novel, manga, and anime series Full Metal Panic!. She is portrayed by Yukana Nogami in the original anime, and by Hilary Haag in the English dub by ADV Films and FUNimation Entertainment. Her name is sometimes spelled Teressa Testarossa.

Source: Wikipedia