Examination subjects offered at Junior Cert include:
- English
- Irish
- Maths
- History
- Geography
- French
- Spanish
- German
- Science
- Art
- Woodwork
- Technical Graphics
- CSPE
- Music
- Business
- Home Economics
Other non-exam subjects include
- Religious Education
- PE
- SPHE
At Leaving Certificate Level, as well as offering non-exam subjects such as PE, Religious Education and Careers, Sligo Grammar School offers the following subjects:
- English
- Irish
- Maths
- History
- Geography
- Biology
- Chemistry
- Physics
- Agricultural Science
- Home Economics(Social and Scientific)
- Art (and Craftwork)
- Music
- Design and Computer Graphics
- Applied Maths
- Spanish
- French
- German
- Business
- Accountancy
- Construction Studies
- LCVP
- LCPE
CASD (Climate Action and Sustainable Development)
Leaving Cert students 2015