Kooloonong is a locality in Victoria, Australia, located approximately 147 km from Mildura, Victoria and was on the Yungera railway line.
The railway north of Swan Hill was extended from Piangil to Kooloonong in March 1920 to support the establishment of soldier settlement farms in the area. For many years water was carted to the location by train because there was no natural water supply. The line from Piangil was closed in December 1986.
Kooloonong was established as a Soldier settlement area for soldiers returning from World War I. By the mid-1920s, it was a thriving township with a bush nursing hospital, government offices, school and RSL hall, railway station and sporting facilities. The town has declined since then and now has only one occupied house plus the rarely-used hall, a CFA shed and unused grain handling facilities.
The railway was further extended in 1926. The terminus was named Yungera and was at what is now the boundary between the localities of Kooloonong and Boundary Bend. It was shortened back to Kooloonong in 1957.
Kooloonong Post Office opened around June 1920 and closed in 1973.