Ages 
‘CGS taught my children kindness, humility and how to push themselves academically without overwhelming them,’ said one parent. ‘I’d sacrifice a GCSE grade 9 for a decent human being.' So would the head, who oversees a school with a friendly, co-ed atmosphere, a great deal of leadership opportunities and confident, independent pupils who are ‘happy to get stuck into everything’.
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Overview & data
- Pupil numbers
- 1,324 ·
- Sixth form numbers
- 410 ·
- Local authority
- Buckinghamshire County Council
- Area guides
Headteacher
Headteacher
Ms Annmarie McNaney BA Hons
Since 2015, Annmarie McNaney BA PGCE. Educated at Bristol University (theology and sociology), then taught at a large comprehensive near Bristol. Joined CGS as head of sixth form in the 1990s, subsequently assistant then deputy head. Lives in
Entrance
Oversubscribed for the 180 year 7 places. Entry via the Bucks Secondary Transfer Test – also known as the 11-plus – at the start of year 6 (pupils in Herts and further afield must be registered during May/June of year 5). Approx 70 feeder schools and
- Admissions policy
- Academically selective state school
Entry and exit data - year 7 entry (average 2020-2022)
Exit
Ten per cent leave after GCSE – a handful don’t make the grade and others leave to do subjects not offered at CGS. Over two-thirds of sixth formers to university, 70 per cent to Russell Group. Birmingham, Nottingham, Manchester, Warwick and Bristol
% students progressing to higher education or training (2021 leavers)
What is this?
The proportion of 16-18 students that progressed to degrees, higher apprenticeships or other study at level 4 or above for at least 6 consecutive months in the 2 years after taking advanced level qualifications (level 3) at this school or college.
Latest results
In 2025, 67 per cent 9-7 at GCSE; 58 per cent A*/A at A level (86 per cent A*-B).
GCSE - % of pupils achieving grade 5 or above (A* to C) in English and maths GCSE (2024)
What is this?
This tells you the percentage of pupils who achieved grade 5 or above in English and maths GCSEs.
A level - Average points score (2024)
What is this?
These figures tell you the average grade and average points that pupils achieved in their academic qualifications. A maximum of 60 points are available for a grade A* at A level.
Teaching & learning
CGS has been edging its way up the league tables and now sits comfortably within the top 40 state schools in the country, a leader among the Bucks grammar schools. ‘Our average GCSE score is 7.5,’ says the head. ‘If your child does what they're told
- Qualifications taken in 2024
- A level
- EPQ
- GCSE
Learning support & SEN
Four per cent are on the SEND register, with up to a dozen EHCPs. But SENCo says the department is ‘needs-led, so a diagnosis is not required to guarantee extra support’. Instead, staff look out for additional needs as they present themselves. SENCo
Arts & extracurricular
We spotted pupil artwork not just in the art room but throughout the school – huge canvases, fashion creations, paintings – as well as displays of photos of productions, art, sports team lists and inspirational quotes. One of our moments of dwelling
Sport
Football, rugby and cricket for both genders, plus rounders and netball for girls. PE compulsory to year 12, optional in year 13. Also on offer are basketball, badminton, gymnastics, volleyball, lacrosse and tennis. Anywhere between 15 to 20 fixtures
Ethos & heritage
Chesham may not have the centuries-old history of Challoner’s or RGS, but it can boast impressive growth since its foundation in 1947, when it was all boys and known as Chesham Technical School. It had a stint as Chesham High School, turned co-ed in
Pastoral care, inclusivity & discipline
School lives up to its core value of kindness, along with aspiration and respect. Vital to this success is the vertical tutor group system: each tutor group meets daily, for a pupil’s whole time at CGS, and comprises three or four children from each
Mobile phone policy
A clear mobile phone policy is a really important part of modern schooling. This school has provided us with their policy.
Mobile phone policy
Provided by the school and not part of our review Students from years 7 to 11 are not permitted to use their phone at any time whilst in school and we take no responsibility for the device unless it is handed into reception where it will be safely stored during the school day. Sixth form students may use their devices at any time in the Curtis Centre area only (outside area, Curtis Centre cafe and the study rooms). Sixth form students may also use their devices in lessons when the classroom teacher deems it to be beneficial to learning and in the canteen if they are using this as a study space in their study periods.
Pupils & parents
Students are universally delightful, confident and chatty. Asked what they’d change, one student fires back, ‘lower canteen prices!’ while another would simply request ‘a wider corridor’ in a busy part of the school. Parents are mainly middle-class
The last word
‘CGS taught my children kindness, humility and how to push themselves academically without overwhelming them,’ said one parent. ‘I’d sacrifice a GCSE grade 9 for a decent human being.' So would the head, who oversees a school with a friendly, co-ed
Inspection reports
Ofsted reports
Full inspection:
You can read full reports on the Ofsted website
| Personal development | Outstanding |
|---|---|
| Quality of education | Outstanding |
| Behaviour and attitudes | Outstanding |
| Leadership and management | Outstanding |
| Sixth form provision | Outstanding |
Full inspection: Outstanding
| Leadership and management | Outstanding |
|---|
