Corpus Christi Catholic College's inspection came after Mrs Maguire, 61, was murdered by Will Cornick, 15, on 28 April 2014.
Ofsted rated the college as "good" in its latest inspection after previously judging it as requiring improvement.
But, the inspectors said "pace of progress was slow and some learning was affected" by the tragedy.
In the report, Ofsted stated: "Leaders, well supported by the local authority and the Catholic community, have mitigated the effects of the critical incident and maintained the focus on school improvement.
"Behaviour in lessons and around the school is good. The calm college atmosphere supports a good work ethic in classrooms.
"The pace of school improvement slowed and some learning was affected by staff absence following the critical incident."
It added students had been "well-supported following the incident and help continues to be available".
In a statement, Corpus Christi Catholic College said it was "delighted" with the judgement.
"It is wonderful that Ofsted has recognised the good progress that has been made despite the challenges that we have faced," it said.
"We are immensely proud of the way that we pulled together as a whole learning community, following the tragic death of Ann last year and we know that she would have been very proud of this judgement.
"Her legacy lives on in the college and we continue to remember her in our thoughts and prayers."
Mrs Maguire was stabbed seven times in a classroom by Cornick during a Spanish lesson at the school, where she had taught for more than 40 years.
She had been due to retire last September.
After his trial at Leeds Crown Court in November, Cornick was detained for life and told by a judge he must serve a minimum of 20 years.
A Leeds school where teacher Ann Maguire was killed has improved despite the murder, inspectors say.