As a founding member of the elite PSA competition, Guildford Grammar School involves itself in a full and varied range of inter-school sporting commitments. Organised competition in athletics, badminton, basketball, cricket,
cross-country running, football, hockey, rowing, rugby union, soccer,
swimming, and tennis,
water polo is offered to every student in the Senior School.
Many of the competitions date back more than a century and although they are fiercely contested, are played in a spirit of camaraderie and sportsmanship.
In the Preparatory School (primary school),
a modified offering of a number of different recreational and sporting activities ensures the students are well trained in the basic skills across a number of codes.
The involvement in both a winter and summer sport is a compulsory requirement of all students at Guildford Grammar School.