Inspectors say Haute Vallée School has 'been transformed' by good leadership and pupil mentality.
An independent Jersey Schools Review has found the school has undergone 'considerable improvement' over recent years.
A team of eight reviewers from the UK visited the secondary school in St Helier over three days in October.
They have praised the leadership, teaching and pupil behaviour.
"This well led and governed school gives very valuable service to its pupils and the community. The school has been transformed, with very considerable improvement in recent years. Pupils ate proud to attend. They feel safe and secure... Most leave with a useful set of qualifications, and an appropriate place in further education."
The team found a large majority of parents are happy with the school, which produces 'calm, kind and productive' children.
Headteacher, Stuart Hughes, says to say he's proud is an understatement.
"I feel absolutely delighted, I'm a very, very proud man.
"What I'm really proud of is the fact that we've had eight reviewers in the school, [they] spent three days with us, had a good look around and turned every stone upside down, and they have stated, -through the evaluation process - that actually, this school is doing very, very well and that it has been significantly transformed over recent years."
The report says attendance is in line with the average of other schools, but that ;occasional misbehaviour by a small minority' of pupils has led to a higher exclusion rate than leaders would like.
Mr Hughes says the school has introduced a behaviour system called 'Ready to Learn', which has been a big success.
"Like every school, there will be a small number of students who have difficulties managing our expectations.
It's always been our plan to consider how we support those youngsters more, and that's about getting to know them and getting to know their families, and working together to support them the best we possibly can so they can engage and amend their behaviour so that they too can successfully learn."
The reviewers would also like to see further development of the curriculum, concluding that there are many strengths, but 'refinement should be considered'.
Mr Hughes says when he first arrived at the school six years ago, he wanted to strip everything back to basics and focus on building good foundations.
"We need to ensure there's a broad and balanced curriculum.
There are things we need to consider going forward in relation to what we deliver in the future."
Mr Hughes said he would like to thank all students, parents, colleagues and School Governors for their 'tireless commitment to the school’s continued evolution'.