Ysgol Llanhari provides a wide-ranging, balanced and differentiated curriculum. It includes the core subjects of the National Curriculum, namely Welsh, English, Mathematics and Science along with the non-core subjects of the National Curriculum, namely Technology, Information Technology, History, Geography, Music, Art, Modern Languages and Physical Education. Religious Education is taught at every Key Stage. 
There will also be an opportunity for every pupil to enjoy Drama lessons as well as other aspects of education which contribute to the student's personal and social development. Information Technology Key Skills are developed through specific lessons on every pupil’s timetable and across the curriculum.
The school places great emphasis on the development of the latest teaching and learning techniques. We encourage teaching methodology that offers our pupils the opportunity to work together, problem solve, work as team members, research and formulate theories and develop opinions and points of view. Such methods develop pupils’ self-respect and self-worth as well as making them independent learners. The development of pupils’ Essential Skills are enhanced and developed in this way.
Year 7
Year 7 pupils are taught in mixed ability classes and lessons are arranged as follows:
 68% of the curriculum:
Welsh (5), English (5), Mathematics (5), Science (5), French or Spanish (4), Technology (4), Good Health (4), Music (1), Drama (1).
 32% of the curriculum:
Integrated Learning Modules (16)
Years 8 and 9
Lessons are distributed in Years 8 and 9 as follows:
Welsh (6/5), English (5/6), Mathematics (6/5), Science (5/6), French or Spanish (4), Technology (4), Physical Education (3), Religious Education (2), Geography (3), History (3), Music (2), Drama (2), Art (2), Information Technology (1), Skills Development (2).
In Year 8 the core subjects, Welsh, English, Mathematics and also Technology will be set across half the year. Other subjects use a variety of teaching groups, mixed ability included. Year 8 also have a general session with the school’s Career’s Officer. The school Career’s Officer takes sessions with Year 9 pupils as part of their options programme. There will be flexible setting of classes in these years.
A Personal Future Programme is delivered to KS3 pupils through the subjects and through weekly sessions during the morning pastoral period.