The Onyx River is an Antarctic meltwater stream which flows westward through the Wright Valley from Wright Lower Glacier and Lake Brownworth at the foot of the glacier to Lake Vanda, during the few months of the Antarctic summer.

Flow levels are highly variable, both during the day and between summers, with the river failing to reach the lake some years.

[3] The Onyx River is one of the many sites studied by the United States Antarctic Program of the National Science Foundation.

[4] The Antarctica New Zealand program once maintained a semi-permanent camp at Lake Vanda which has since been removed.

NSF's McMurdo Long Term Ecological Research site has been maintaining the Onyx River record since 1993.