Eucalyptus sargentii, commonly known as Salt River gum,[2] is a species of mallet, mallee or small tree that is endemic to Western Australia.

Eucalyptus sargentii is a tree or a mallee that typically grows to a height of 3–12 m (9.8–39.4 ft) but does not usually form a lignotuber (a mallet).

[11][12] Subspecies onesis differs from the autonym in having a lignotuber and a dense, spreading mallee habit.

[11] The name onesis is from an ancient Greek word meaning "advantage" or "use", referring to the potential use of this subspecies in reclaiming saline sites.

[4][5][11] Subspecies sargenti is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife,[14] but subspecies onesis is classified as "Priority Three" by the Government of Western Australia Department of Parks and Wildlife[2] meaning that it is poorly known and known from only a few locations but is not under imminent threat.