The Student Parliament represents the student body at JMSS. They drive student initiatives within the school in areas such as music, the environment and fundraising for charitable organizations. Parliament members prepare written proposals in which they present during Student Parliament meetings. The Parliament is comprised of 44 elected members including School (and Vice) Captains, House (and Vice) Captains and Sub-Committee members from the six Sub-Committees (Culture and Community Outreach, Environment, Media and Communication, Performing Arts, Science, Maths and Technology and Sports and Recreation).
A new Student Parliament is elected every year with positions held by students in Year 11 and 12. Additionally, four Year 10 Representatives, assigned to a Sub-Committee are chosen each term. Students are elected by the Houses they represent, with the exception of the School Captains who are elected by the Principals. Students that are not elected as members are encouraged to attend meetings and contribute. The Parliament meets every Monday at lunchtime.