A clean sweep of A*-A grades was achieved in seven subjects including Chemistry and Biology. In Physics, nine in ten girls also achieved A*-A grades.
The Berkshire school, headed by Chemistry graduate Mrs Jo Heywood, has driven forward the study of sciences at the school alongside a push on other rigorous academic subjects. Building work has already begun on a state-of-the-art new STEM (Science Technology Engineering and Mathematics) block at Heathfield.
Other subjects with A*-A grades across the board include Art and Design and Geography.
Outstanding individual GCSE performances this summer also include those of two girls who were awarded 12 GCSEs each with 16 A* grades and 7 A grades between them.
Girls also scored impressively in modern foreign languages with over three-quarters (77%) scoring A*-B grades in French, 80% scoring A*-B in Spanish and all A* grades in German, Chinese and Russian.
Other top-performing subjects include Religious Studies (96% A*-B), History (89% A*-B) and English Literature (83% A*-B).
Head of Heathfield School, Mrs Jo Heywood, said: ‘These outstanding performances at GCSE show great promise for the future and validate our drive to raise academic standards at Heathfield to the highest level. I am particularly delighted that more girls are studying sciences at GCSE with the very highest grades.’