Castletroy College has excellent facilities for students and staff.
- 38 General Classrooms equipped with a computer, data projector and media facilities.
- 6 Science Laboratories
- 4 Science Storage Rooms and Chemical Stores
- 2 Art Rooms
- 4 Information Technology Rooms
- 2 Design & Communication Graphics Rooms
- 3 Woodwork/Construction Studies Rooms
- 2 Metalwork/Engineering Rooms
- 2 Home Economics Rooms
- 1 Music Room
- Library & Open Space
- 5 Resource Rooms with Chromebook Access
- Senior General Purpose Area with Kitchen
- Junior General Purpose Area with Kitchen
- Industry Standard Wireless Network Access
- Mobile Chromebook Access Solutions
- 1 Gym Hall
- 1 Fully Equipped Gym
- 4 Outdoor Basketball Courts
- 4 Outdoor Tennis Courts
- 1 GAA Pitch
- 2 Rugby Pitches
- 3 Astro Turf Pitches
- Student Changing Rooms x 10
- Pastoral Care Room
- 2 x Guidance Counsellors Offices
- Isolation Room
- Board Room
- Prayer Room
- 3 Teacher Work Rooms
- Staffroom
