Theatre Ong took on the post of artistic director of theatre group TheatreWorks in 1988. He was involved with the production of comedies such as
Beauty World and
Army Daze. His local productions include Destinies of Flowers in the Mirror and Descendants of the Admiral Eunuch. Ong was the director of
Singapore International Festival of Arts (SIFA) from 2014 to 2017. The SIFA was a revamped, independent version of its predecessor, the
Singapore Arts Festival. Ong was invited to recreate this national performing arts festival after an industry review. He was the first artist to helm the festival since the festival's inception in 1977, which had previously been headed by
civil servants. In this capacity, he sought to ensure the sustainability of the festival. Ong restructured the festival and renamed it SIFA to highlight the Singapore and international perspectives in it. Beginning with 20,000 audiences in SIFA 2014, this has increased to 62,000 and in 2016, the festival peaked with 155,000 attendances, 96% capacity houses and 75% of its performances sold out. Further in 2016, he was responsible for raising 20% of the S$9 mil festival through sponsorship. During his tenure, he has brought international artists to work with Singapore art schools. He has capacity-built cultural development through his scaffold of an alternating international and local focus for SIFA from year to year. As festival director, he has been vocal about the government restrictions and non-transparent
OB markers for performance arts staged in Singapore. In addition to serving as festival director, Ong has directed one performance every year at the festival. Ong directed
Facing Goya, a
Michael Nyman-composed opera, for the opening of Singapore International Festival of Arts 2014. In 2015, Ong directed a six-hour site-specific performance,
The Incredible Adventures Of Border Crossers, for the opening of the inaugural Singapore Festival in France at the
Palais de Tokyo. The production involved 30 foreigners and explored what it meant to be a "border crosser". The festival also re-staged at Theater de la Ville Paris,
TheatreWorks'
Lear Dreaming, directed by Ong. In the same year,
Lear, directed by Ong and written by
Rio Kishida, was selected by
The Business Times as one of the "finest plays in 50 years" alongside productions by
Goh Poh Seng,
Michael Chiang and
Alfian Sa'at and others. In 2016, Ong created Sandaime Richard based on Hideki Noda's script of the same title with kabuki onnagata Kazutaro Nakamura as Richard III. This gender bending production at Tokyo Metropolitan Theater was followed by a new production of Trojan Women at the National Theater of Korea, showcasing a blend of pansori, K-pop and Greek tragedy. In particular, the show gained much attention by casting a male pansori singer as Helen of Troy.
Film Ong directed the Singaporean film
Army Daze, based on a play written by
Michael Chiang. The movie was released in 1996. ==Themes and style==