This species occurs in every state/territory of Australia, including Tasmania – there isn’t the slightest gap on its distribution map. It is also recorded in Indonesia and Papua New Guinea.
In the abdomen this species looks very like our European O. cancellatum (Black-tailed Skimmer). However the pterostigmas of O. caledonicum are yellow (as opposed to the black of O. cancellatum) and there is a noticeable bronze tint to the distal [outboard] section of the wings.
We found our first around the Beechworth area, Victoria, both beside the waterfalls of the Beechworth Historic Park (Spring Creek) and at Lake Sambell in Beechworth itself. During my 2-week trip around southeast Queensland in 2019, I encountered it many times and saw females for the first time.