鼎脉灰蜻 （学名：Orthetrum triangulare）是蜻蜓科下的一种蜻蜓，见于亚洲的山地、池泽地区。

Orthetrum triangulare is an Asian freshwater dragonfly species. It is usually found in hilly and montane areas, and breeds in small ponds and marshy areas, and is tolerant of disturbance. The common name for this species is Blue-tailed Forest Hawk.