The Junior School opened in 1994, in accommodation previously occupied by boarders. MCS had previously educated below the age of 11 only choristers: now it became possible to create an intimate Junior School of the highest quality for boys aged 7 to 11.
The MCS Junior School is accommodated in School House, beside the River Cherwell and opposite the main school site in Cowley Place. Boys are admitted primarily at age 7 into J1 (year 3). There is the possibility for boys to join MCS aged 8 into J2 (year 4), aged 9 into J3 (year 5) and sometimes aged 10 into J4 (year 6), dependent on the availability of places. In addition to its own accommodation in School House, the school has full access to all the facilities on the Senior School site, and all other related facilities, such as college sports grounds.
The Junior School is an integral part of MCS. It has its own Head, Mr Tim Skipwith, and a dedicated Common Room of specialist junior teachers, whilst being under the overall direction of the Master, and having access where appropriate to Senior School staff, as well as to Senior School facilities.
The school prides itself on the quality of its Pastoral, Academic and Extra Curricular provisions, and there is an outstanding record of success in the entrance exam at 11 to the Senior School.
The Junior School runs a daily after school care service for all Junior School pupils until 5.30pm. Supervisors oversee these sessions and report to the Deputy Head of Junior School. There is opportunity for homework to be completed before indoor and outdoor activities to commence.