ST Louis is synonymous with academic success - its motto talks about promoting "excellence, endeavour and empowerment".
It has a consistently impressive academic profile and places an emphasis upon rapport at all levels throughout the school.
It provides more than 1,000 pupils, from 11-19, a friendly, caring and competitive learning environment.
Opened in 1925, it has earned many accolades for high quality learning and teaching experiences since those early days.
It has topped The Irish News grammar school league tables for the last three years.
Now, for the first time since A-level performance lists were re-introduced, the Ballymena grammar has achieved something no other school has - a 100 A*-C per cent pass rate.
Read More: School performance lists: New Catholic school St Kevin's takes top spot
Securing three or more A-levels at grades A* to C is considered a reasonable expectation of grammar pupils.
Most academically selective schools are geared towards taking these exams.
Using newly-published statistics for the 2018/19 academic year, The Irish News today ranks the top 30 schools by the proportion of pupils achieving the three A-level standard.
St Louis had the highest proportion of pupils achieving top marks - 100 per cent, up from 96.5 and 95.3 per cent in the previous two years.
The school had 163 students in the year group and all scored at least three A*-C in A-levels or equivalent qualifications.
It runs a mixture of courses for sixth formers that also include vocational A-levels.
"To say we as a school are delighted with last year's public examination results would be an understatement," said principal Sean Rafferty.
"The whole St Louis Grammar School community is thrilled and the outstanding results really reflect both the positivity and the spirit of teamwork that we encourage at all times inside the classroom and beyond.
"As a school we pride ourselves on ensuring our students gain successful outcomes at GCSE/GCE and this year once again we have surpassed those internal challenging targets with the 100 per cent figure. To have every student in sixth form leave St Louis with an exceptionally strong academic profile is a really huge advantage for them whether students decide to pursue high demand courses at university or follow the higher national apprenticeship route."
Attaining such excellent results across a large cohort of pupils, and across a wide curricular offer, reflected the school's academic strengths, Mr Rafferty added.
"While this year's results have been magnificent, we are also aware that over the last number of years SLG has been a top performing school in NI and that these results from our students merely consolidate our achievements of the past as well," he said.
"Consistently outstanding academic outcomes such as these, over a number of years are the combination of engaged students, deep curriculum planning, high quality learning and teaching experiences for students, rigorous tracking of student progress, supportive parents and of course a superb teaching staff.
"As a school we are constantly monitoring and evaluating all aspects of curriculum delivery including engaging with our students regularly to ensure our students are not only achieving highly, but are both happy and enjoying their learning too."
Across the north, A-level performance remains strong with the number of top A* grades on the rise.
Maths remains the most popular A-level, with one in every 10 pupils studying the subject.
The proportion taking `stem' subjects and languages is in decline, however stem continues to account for more than one-third of A-level entries.
The Department of Education advises that exam data takes no account of intakes of schools or of any other factors that may affect pupil performance.
However, The Irish News' annual list does not intend to suggest that one school is better than another, or that academic performance should be the sole criterion for judging the quality of education on offer.
It has been often argued that grammar schools can usefully be compared on the basis of exam performance.
In addition, The Irish News performance lists are anticipated annually and some schools advertise their positions on their websites.
