The Senior School starts with our Grade 8 students who will be 11 years of age. It is a special building, built around departments namely the Sciences (Physics theory and practical room, Chemistry Laboratory, Biology Laboratory and Technology Room) and Mathematics, Humanities (History, Geography, Environmental Studies, Religious Studies, Accounts, Economics, PSHE), Languages (Maltese, English, Italian and French), 2 ICT / Computer Studies Suites, Practical Subjects (Physical Education, Drama room, Art room & Home Economics Lab).  These departments serve the need of students between the ages of 11 and 16.

The school is also equipped with a library.  The San Andrea School Library was established to support the curriculum of the senior school in which it is located. The mission of San Andrea Senior School Library is to ensure that students and staff are effective users of ideas and information. The school library supports the educational curriculum, collaborates with the teaching staff in creating assignments and projects which utilizes the library, fosters reading and literacy in all students and teaches patrons how to locate, evaluate, synthesize, and effectively use the information.

This year the school also invested in the development of a meditation room ‘Shekinah’ or ‘God’s dwelling amongst us’.  This room aims at providing the space for quality quiet time which is a needed necessity in the fast world we live in.  This room was blessed and inaugurated by the Archbishop of Malta Mons. P. Cremona O.P.  as part of the 15th year anniversary of the school.

The school also boasts of an outer astro-turfed sports facilities which include a tennis court, 2 five-a –side or one 7-a-side football pitch, sand pit area for long-jump, shot put area, high jump mat, hurdles, 2 mini basketball courts, 2 full-sized volleyball courts and one multi-purpose basketball/tennis court and a four-lane athletics rubber-track (160m inner lane, 175m outer lane).