The Department for Education performance tables reveal that Gainsborough Academy is among 10 per cent of schools in the UK which are “well below” the national average.
The results show the school has a score of -1.05 in the new Progress 8 score, which shows how much progress pupils made between the end of Key Stage 2 and the end of Key Stage 4.
A score below zero means pupils made less progress, on average, than pupils across England who got similar results at the end of Key Stage 2.
David Miller, academy headteacher, said many of the problems at the school had now been “addressed”.
He said: “Some of our students did very well indeed.
“Our results in vocational subjects were good and the academy’s five A*to G pass rate remained high.
“The progression rates to further study were really good, due to the links we have built up through our careers programme with a variety of post-16 providers.
“Our school is a much calmer and business like environment after the positive discipline actions that we took last year around behaviour.
“However, we had some legacy curriculum issues in the 2015/6 year which hampered achievement in some areas of the academy. These have now been addressed.
“As always, we look forward. Our Year 11 students and our staff are working hard and we are expecting sustained improvement with this summer’s results.“
The town’s Queen Elizabeth’s High School has a 0.01 score in the Progress 8 score, which means it is within the 40 per cent of schools at average level.
David Allsop, headteacher, said: “We are delighted so many of our students attained the grades needed to progress in their education – 100 per cent of our students gained A* to C in English and maths and this meant every single student was able to progress to high-quality employment, education or training post-16.”