The Triathlon at the 2005 SEA Games was held at the Boardwalk, Subic Bay Freeport Zone, Zambales, Philippines on December 1 and 2. The participants are competing for individual gold medals in the men's and women's events.
The SEA Games distances for the three disciplines are: ;br ;
Swimming - 1500 m ;br ;
Road cycling - 40 km ;br ;
Road running - 10 km
The events will run in sequence, so that the person who crossed the line in first place at the end of the run is declared the winner.