There are many opportunities for students of all years to represent Kirrawee High School in the competitive NSW Combined High Schools Knockout Competitions as well as other Interschool activities such as
| Baseball | Basketball | Cricket |
| Oztag | Rugby League |
Skiing and Snowboarding |
| Touch Football | Football | Futsal |
| Tennis | Water polo | Lawn Bowls |
| Squash | Netball |
Kirrawee High’s water polo program is very well established with many students also participating in external competitions. Kirrawee High has won the Boys and Girls Open and U/15 State Knockouts on many occasions. Kirrawee High has a strong sporting tradition. Teams are entered in a large number of state-wide knock out contests that have been highly successful. The school has had many outstanding individual achievements including NSW and Australian representatives and/or champions in swimming, athletics, football, futsal, gymnastics, cricket, water polo, softball and netball.
Each year Kirrawee has about 80 to 100 students who represent the Sydney East Region at State Championships, particularly in swimming and water polo. Students wishing to trial for a Sydney East team must complete a nomination form, gain permission from the sports organiser and get signed off from the office to ensure they are recorded as School Business.
Each year the school conducts a swimming and athletic carnival. These are whole day events and are compulsory for all students. A one day cross country carnival is held for interested students. These carnivals are always a fantastic day together as a school community.