Catholic High School, Petaling Jaya

CHS has made appearances in the arena of ultimate frisbee. In 2006, CHS competed in the UM Open, sending three teams (one Open, one Men's Novice, one Women's Novice).[8] In 2007, CHS sent a few representatives to join All Star at the Valley Ultimate's Hard-Core Ultimate Frisbee[9] and also sent five teams to make a clean sweep at the Subang Jaya Community Youth Under-18 Ultimate Open.[10] In 2008, CHS competed in competitions such as the UiTM Open, where the team received the title of Most Promising Team[11][12] and Taylor's Ultimate Mini.[13]

The cheerleading team for Catholic High is Calyx. They won the Best Dressed award, Best Make Up award and also Second Runner Up for the Cheer2009 national cheerleading championships.[14] The team put in a brilliant performance to finish second in the All-Girls category in Cheer 2015.[15] In Cheer 2018, Calyx All Girls from SMJK Katholik overcame an eight-time winner to clinch the top prize. It broke the winning streak of defending champions, Cyrens from Sri Kuala Lumpur, which had been No.1 for eight years. Calyx captain Tung Mei Yee, was elated that their hard work paid off.[16]

Foong Yake Ho and Liew Chien Hao represented Malaysia to compete in the 39th International Mathematical Olympiad in Taipei, Taiwan in the year 1998. In the same year, Foong won a bronze medal in the Asian-Pacific Mathematical Olympiad while Liew won a bronze medal in the Southeast Asia Mathematical Olympiad. In the following year, both Foong and Liew represented Malaysia in the 40th Mathematical Olympiad held in Bucharest, Romania. They won a consolation prize and bronze medal respectively in the Asia-Pacific Mathematical Olympiad held in 1999.[17]

The 2nd Sunway University College Inter-School Math Quiz Challenge 2007 Finals held at Sunway University College was won by Form 5 CHS students Cheong Tee Jin, Bryan Chong Hau Foo, and Tan Jing Lynn. Cheong Tee Jin represented Malaysia in the International Math Olympiad in Slovenia in the year 2006.[18]

Catholic High student Tham Ying Hong represented Malaysia and won the Silver Award in the 51st International Mathematic Olympiad organized by the Ministry of Education and Science of the Republic of Kazakhstan in the year 2010. In the year 2011, he won the gold medal in the Australian Mathematics Competition, gold medal in the 23rd Asia Pacific Mathematics Olympiad and bronze medal in the 52nd International Mathematical Olympiad in Amsterdam, Netherlands.[19]

Yeoh Chin Vern is the bronze medalist in the 2013 44th International Physics Olympiad held in Copenhagen, Denmark.[20]

A team of three boys from Catholic High School PJ won a gold medal in the lower secondary category of the 2019 World Robot Olympiad held in Győr, Hungary. They built a diagnostic and surgical robot.[21]

SMJK Katholik emerged champion in the 2005 National Level High School Brass Band Competition held in Penang. Education Ministry general Tan Sri said SMJK Katholik had set a very high standard in brass performance for others to use as a benchmark.[22]

The school band won the Silver Award in the Singapore International Band Festival in 2010 organized by the Wind Bands Association of Singapore. From 29 November 2011 to 3 December 2011, the Catholic High School Band participated in the international 3rd Winter Band Festival 2011 at Hong Kong Disneyland Resort, and won a Gold Award. The CHS Band was also the first Malaysian band to perform in the Art of Animation Studio, Disneyland, Hong Kong.[5]

A team of students from Catholic High took the champion title in the national Built Environment Explained Competition 2013 organized by Taylor's University, winning a total cash prize of RM 2800. The theme given on that year was Designing Better Classrooms.[23]

CHS Chinese Debate team won the Championship in the National Secondary School Chinese Debate Competition in the years 1999, 2001, 2002 and 2003.[24]

In the year 2016, one team from CHS was inaugurated as national champions in the FedEx-Amcham International Trade Challenge,[25]