Merewether High School offers many extracurricular clubs and activities to its students, many of them
musical ensembles, including: string ensemble, percussion ensemble,
orchestra,
jazz band,
concert band, saxophone quartet, flute quartet, clarinet quartet, vocal ensemble and guitar ensemble, formerly facilitated by the honourable Brian Saxby
BMus. Other activities and clubs at the school include a chess club, art club, and robotics club. Merewether High School has participated in
Odyssey of the Mind since at least 1992 and have had many successes in this pursuit, including a team of Year 9 students winning the Ranatra Fusca Creativity Award in 2008. The school has many various sporting teams including: cricket, association football, basketball (The Weathers), rugby union (Merewether Moos), rugby league,
Australian rules football, hockey, netball, volleyball, rowing, aerobics team, water polo, tennis, table tennis softball and baseball. Merewether High School regularly participates in the
World's Greatest Shave, with several staff and students shaving their hair to raise money for leukaemia research. In 2021, the school raised over $78,000. In 2022, the school was able to raise over $100,000, the most of any school in Australia. Merewether High School was one of the schools that competed on the
Network 10 programme
Shaun Micallef's Brain Eisteddfod. == Notable alumni ==