Independent School Inspectorate (ISI)

In our most recent Independent School Inspectorate (ISI) report, we were delighted that John Lyon met all of the required standards.


Pupils look after each other, are compassionate and exhibit a willingness to volunteer, all of which are reflective of the School’s aims.

Independent Schools Inspectorate, 2024

We are delighted that John Lyon School has met all of the required independent school standards and also that the Independent Schools Inspectorate (ISI) recognised how we are providing quality academic, co-curricular and pastoral outcomes for our pupils. We were very pleased with the wonderful feedback we received from the inspection team, which confirms our commitment to offering the very best, rounded educational experience to our pupils.

For the first time in its history, John Lyon was inspected as a 3 to 18 co-education school, with the ISI visiting all three of our campuses: Prep School, Senior School and Sudbury Fields.

It is worth nothing that, as of September 2023, the ISI has been operating inspections within an entirely new framework which varies hugely from previous inspections. Therefore, comparisons with our previous inspection reports and that of other schools’ reports before this time are not like-for-like.

Whilst we were previously graded ‘excellent, excellent’ in the Prep and Senior Schools, the new style of inspection reports now simply state whether a school has met or not met the required standards.

John Lyon School is pleased to have met all Independent School Standards:

  • Leadership and management, and governance
  • Quality of teaching, training and recreation
  • Pupils’ physical and mental health and emotional wellbeing
  • Pupils’ social and economic education and contribution to society
  • Safeguarding

Click here to view the full 2024 ISI report.

Historic ISI Inspection Reports

Senior School:

Prep School:

Please note that reports from both the Independent Schools Inspectorate and the Good Schools Guide were commissioned prior to the merger between John Lyon School and Quainton Hall School in November 2020. Quainton Hall School since become part of John Lyon School, as our Prep School, and was rebranded to be part of the John Lyon family in January 2024. Click here to read more about the rebrand.

Pupils are eloquent, think clearly and communicate with confidence.

Independent Schools Inspectorate, 2024

John Lyon prepares pupils well for life after they have left school. Pupils are ambitious and they are well supported with a careers programme that provides personal guidance. They leave the Sixth Form to go on to a range of courses, many of which require a high level of academic achievement.

Independent Schools Inspectorate, 2024