In Years 5 and 6, St Leonard's students compete in a range of sports in the ACS Junior sport competition, against other coeducational independent primary schools. The college is part of the
Association of Coeducational Schools (ACS) sports competition which involves other independent co-educational schools around Melbourne. Participation is mandatory in years 7-11, and optional for year 12 students. Students participate in a range of team sports, through the summer and winter seasons, as well as the carnival sports of cross country, swimming and athletics. St Leonard's College also has a club sport program, providing a number of opportunities for students, parents, staff and alumni to be involved in sport and fitness activities. Aesthetic Sports, Equestrian, Sailing and Taekwondo are some of the activities available. There are also club basketball, netball and swimming clubs. and also regularly competes at the National Championships. The Hawkes Sports Centre has a large indoor pool, tennis courts, aerobics room, gym, multi-purpose hall and change rooms. The college also has outdoor hard courts and an oval. St Leonard’s College has enjoyed significant success in ACS sport, winning the following Senior 1sts competitions since the inception of the ACS in 1998:
ACS Carnivals • Athletics (10) – 1998, 1999, 2000, 2001, 2002, 2014, 2018, 2019, (2020 Cancelled due to COVID-19), 2022, 2024 • Cross-Country (11) – 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2014, 2015, 2016, (2020 and 2021 cancelled due to COVID-19) • Swimming (13) – 2000, 2005, 2006, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024
Girls Premierships: • Basketball (4) – 2004, 2011, 2012, 2025 • Football (4) – 2019, 2022, 2023, 2024 • Hockey (4) – 2022, 2023, 2024. 2025 • Netball (14) – 2001, 2002, 2003, 2004, 2010, 2011, 2014, 2015, 2016, 2017, 2018, 2023, 2024, 2025 • Soccer (5) – 2004, 2013, 2019, 2020, 2025 • Softball (5) – 2002, 2003, 2004, 2005, 2019 • Tennis (1) – 2015 • Volleyball (8)– 1998, 2000, 2001, 2002, 2004, 2020, 2021, 2022
Boys Premierships: • Basketball (8) – 2001, 2004, 2009, 2014, 2015, 2016, 2021, 2024 • Cricket (3) – 2012, 2014, 2016 • Football (2) – 2016, 2022 • Hockey (4) – 1998, 2020, 2021, 2024 • Soccer (3) – 2003, 2009, 2014 • Softball (1) – 2020 • Table Tennis (4) – 2022, 2023, 2024, 2025 • Tennis (2) – 2006, 2019 • Volleyball (1) - 2024
Mixed Gender ACS Premierships: • Touch Football (7) – 2013, 2014, 2015, 2016, 2017, 2018, 2021 (no longer an ACS Sport) • Beach Volleyball (4) – 2014, 2015, 2016, 2019 (no longer an ACS Sport) • Lawn Bowls – 2025 (introduced in 2025)
ACS Championships: • Chess (7) – 2009, 2010, 2016, 2019, 2020, 2021, 2023 ==Debating and Public Speaking==