Cambodian prime minister Hun Sen and Thailand deputy prime minister Prawit Wongsuwan were among the dignitaries watching on along with athletes from all 11 of the Asian countries.
The ceremony featured musical and art performances, as well as a parade of some of the SEA Games competitors.
Vietnam has won the highest number of gold medals (136) at the current SEA Games in Cambodia, which conclude today (May 17), followed by Thailand (108), Indonesia (86) and Cambodia (81).