At Dorothy Stringer, the number of students achieving a grade 4 or higher in both English and maths has increased from 76 per cent to 82 per cent.
And results in maths have increased markedly at the Brighton school, with 85 per cent achieving a Grade 4 or higher, up from 77 per cent last year.
Science results have continued a four-year trend of improvement, increasing by over 10 per cent to 83 per cent.
Related stories: GCSE results for Brighton and Hove – our live round-up
Attainment 8, the new measure which takes into account a range of eight GCSEs has further improved to 55.37.
Over a third of all grades were at grade 7 (A) or higher
And 155 Grade 9s – the new highest grade – were achieved.
The school said 40 students achieved eight or more GCSEs at grade 7 (A) or higher, with three students gaining eight or more GCSEs at the new Grade 9 or equivalent.
More than 100 students in Year 9 also took GCSEs two years early, mostly in French, with 62 achieving a grade 7 or equivalent.
One 14-year-old student achieved Grade 9s in both French and computer science.
Florence Unwin secured nine grade 9s and two A*s, putting her among the top 200 students in the country.
She said: “It’s unbelievable; I had no idea; I had absolutely no idea.
“I was hoping for a 9 in English maybe.”
Florence will now attend BHASVIC sixth form, where she wants to study English Literature, Modern History and Psychology before going to university.
Reuben Joiner-Brown said: “I largely got 9s, one 8, a couple of A*s and a couple of As.”
Reuben said: “I feel pretty happy. Hard work has paid off over five years; it feels right.”
He plans to study architecture in the future and is looking at a number of universities, including UCL.
Nancy Farris achieved eight 9s, one A*, one 8 and an A.
Nancy said: “I’m so happy; I’m over the moon.
“I don’t even know what to think.”
She now plans to attend Varndean College to take the IB before possibly applying for a place at Oxford or Cambridge.
Her sister, Ruth, also did well, securing 5s, 6s, 7s and an 8.
She felt ‘so relieved’ and will join Nancy at Varndean.
Headteacher Richard Bradford said: “I am once again delighted with the success of our students in this year’s GCSE examinations and the continued improvement in our results.
“In what has been a very challenging year and, in a period of transition and uncertainty for GCSE examinations, the results reflect the hard work and commitment of our students and staff.
“I am incredibly proud of our students this year – they have been a wonderful year group who have been resilient and challenged themselves to do their very best.
“I would also like to thank and congratulate the staff, parents and the wider community who have done so much to support our students over the last few years. I know that without this support the students would not have achieved so much academic success.
“I hope that for the students their time at our school has been a happy one and they will have wonderful memories to look back on. We wish them the best of luck as they go on to the next stage in their lives.”
Additional reporting and video by Axel Fithen.