The JCRs activities fit 7 main themes:

• Representation & Assistance - The JCR represents student views to college and university management. Individuals members are able to seek assistance from the JCR in their dealings with the college or university.
• Facilities - The JCR manages a number of facilities on behalf of the college including: a gym, music room, common room and art room.
• Sports and Societies - The JCR part-funds and administers over 30 student-led sports clubs and societies covering a wide range of interests from rugby and netball to baking and parachute games.
• Volunteers Positions & Student Democracy - Over 100 officer and committee positions are available allowing students to gain key skills in management, administration and team working. An 11 member executive committee is elected by the student body and led by the sabbatical JCR President (traditionally known at Hatfield as ‘Senior Man’).
• Social events - The JCR maintains a varied social calendar with events large and small. The highlight of the calendar is the Lion in Winter Ball, administered by the JCR on behalf of the college. The JCR also assists in the administration of college formal dinners which occur between once and twice a week.
• Inclusion and diverse communities - Through the JCR's "communities" structures, groups requiring additional representation are accommodated. Currently the JCR has these structures for People of Colour, International students, Women, Disabled and mature students. Communities help create inclusive groups and safe spaces for these people and campaign on issues effecting these groups.
• Welfare - Peer-led welfare provision includes supply drops, campaigns (on issues such as sexual health, body positivity and imposter syndrome) and drop-in hours where reps actively listen to students and signpost them appropriately.