St. Mary’s offers a three year Junior Cycle to prepare students for the Junior Certificate at the end of their third year. Students then go on to complete state examinations in ten subjects. A New Junior Cycle has been introduced in recent years. Students will experience newly developed subjects and short courses and will find that their learning has a significant focus on key skills and wellbeing. The new junior cycle will place the student at the centre of the learning process. It allows for new ways of learning and
a broader range of skills to be properly assessed. These skills will largely be assessed through a new form of continuous assessment known as Classroom-Based Assessment (CBAs). We have listed below the subjects that contain CBAs and the year that they were introduced to First Year pupils.
Students have the option to enter a Transition Year programme in their fourth year. The junior cycle course on offer is comprised of compulsory and optional subjects.
The following subjects are offered to Junior Certificate Level;
| Compulsory | Optional |
| English | Art, Craft & Design |
| Gaeilge | Music |
| Mathematics | Wood Technology |
| Civic Social and Political Education (CSPE) | Home Economics |
| Geography | Business Studies |
| History | Technology |
| Science | Technical Graphics |
| French or German or Spanish | – |
| Computer Studies | – |
| Religious Education | – |
| Social Personal and Health Education (SPHE) | – |
| Physical Education (PE) | – |
The following subjects have elements of Classroom-Based Assessment (CBAs);
| Subject | Year Introduced to 1st Years |
| English | 2014 |
| Science | 2016 |
| Business Studies | 2016 |
| Irish | 2017 |
| Modern Languages (French/Spanish/German) | 2017 |
| Mathematics | 2018 |
| Home Economics | 2018 |
| History | 2018 |
| Music | 2018 |
| Geography | 2018 |
| Technology | 2019 |
| Wood Technology | 2019 |
| Technical Graphics | 2019 |
| Religious Education | 2019 |