Pupils from Northamptonshire were among the high achievers at Kimbolton School.
Fifty-six per cent of the grades were awarded at A* or A, and 27 pupils, more than a quarter of the year group, received at least nine A*/A grades.
Ninety-six per cent of the pupils achieved five or more passes at A* to C grade (including maths and English), the standard measure of GCSE attainment.
Included in these results are those for International GCSEs in French, mathematics, physics and Spanish.
Leading the way was Fiona Denton from Ellington with nine A*s and one A each.
Other top performers were Nathanael Warwicker (Rushden) with eight A*s and two As, and Emilia Edwards (Lowick) and Olivia Gerard-Pearse (Aldwincle) with seven A*s and three As.
All of the above plus the vast majority of the rest of the year group will be continuing in Kimbolton School’s sixth form next month where they will be joined by a number of students from other schools.
Pupils with all A*/A grades and at least five A*s included Phoebe Simpson (Barton Seagrave).
Headmaster Jonathan Belbin said: “We are very pleased with this strong set of results which again demonstrates the ‘added value’ that we provide.
“Our pupils represent a relatively broad ability range and their dedication to hard work, alongside the support of all our staff, has shone through once more.
“These results include many IGCSEs of course, a qualification that we believe prepares students well for the challenges of A Levels and beyond, even though they are no longer included in the Government’s spurious ‘league tables’.”