The Avoca River, an inland intermittent river of the north–central catchment, part of the Murray-Darling basin, is located in the lower Riverina bioregion and Central Highlands and Wimmera regions of the Australian state of Victoria.

The headwaters of the Avoca River rise on the northern slopes of the Pyrenees Range and descend to flow into the ephemeral Kerang Lakes.

Two major distributaries leave the Avoca River between Charlton and Quambatook: Tyrrell Creek, flowing to Lake Tyrrell, and Lalbert Creek flowing to Lake Lalbert.

[7] Most of the water flowing in the Avoca River originates in the small upper portion of the catchment area, where rainfall averages about 600 millimetres (24 in) per year,[5] most of it falling in the winter and spring.

Little use of the river is made for irrigation because, during the peak demand periods of summer and autumn, it is often not flowing.