Triarius (disambiguation)

Triarius was a Gothic nobleman and soldier.

Triarius may also refer to:
 * Triarius (tree), an 86.5-metre-high Eucalyptus regnans (swamp gum tree) in Tasmania
 * Triarius (beetle) is a genus of skeletonizing leaf beetles in the family Chrysomelidae
 * Triarii, elements of early Roman military legions, consisting of wealthy and older men