Inspectors said Allerton High School's "exceptional" headteacher Elaine Silson's leadership has "transformed the school."
Ofsted previously rated Allerton High on King Lane in North Leeds as 'good' overall following an inspection in February 2018.
Now Allerton High has been rated as 'outstanding' overall following the latest inspection in December 2018.
The Ofsted report states: "The headteacher is exceptional. Her leadership has transformed the school.
"Not only do pupils make phenomenal progress and reach high standards, but they also develop into well-rounded individuals who are ready to take their place in society.
"They have a thirst for learning and are committed to their education.
" At the heart of leadership at this school is a dogged determination to ensure that every pupil receives the schooling that they deserve. Nothing but the best will do."
Inspectors added in the report: "The headteacher is ably supported by her senior team and members of the governing body.
" Leaders know their school well. They work relentlessly to make their school even better. They are highly effective in improving standards of provision.
"The school now has a history of outstanding outcomes for its pupils. Pupils make sustained progress across the curriculum and the standards that they reach are high."
"Allerton High is a harmonious community. Pupils show high levels of respect towards other pupils and with adults in school.
"Pupils actively support each other and celebrate differences.
"Pupils show excellent attitudes to learning. There is a thirst for knowledge and an excitement about lessons."