RIPON Grammar School's outstanding progress at GCSE has placed the school 81st out of 6,000 schools in the country.
Provisional results for 2019 have been published by the Department for Education, featuring the grades achieved by the third set of pupils to sit new and tougher GCSEs in English and maths.
The scores, designed to encourage good quality teaching across a broad curriculum, measure the progress children make between the end of primary school and their GCSEs.
The national average for all schools in the country is around zero, with a score of +1 meaning pupils achieve one grade higher in each qualification than other similar pupils nationally. RGS scored +0.92, placing it among the top 15% of schools in the country.
Schools are judged by recently introduced measures called Progress 8 and Attainment 8, which are based on the results of the 2019 GCSE exams and historical DfE data.
The school's Attainment 8 score - the average score taken across eight subjects at GCSE - is 72.4, with the national average across all state-funded schools in England being 46.5 and North Yorkshire's average 48.6.
Headmaster Jonathan Webb said: "This is a superb achievement and a credit to everyone at RGS, especially during a time of unprecedented change in the exam system. We are very proud of all our dedicated and hardworking staff and students who rose to the challenge to exceed all expectations."
RGS students achieved 92.9% of all grades at 9-5 (the equivalent of A*-B) in their GCSEs.