Dong Ap Bia (Ap Bia Mountain) is a mountain on the Laotian border of South Vietnam in Thua Thien-Hue Province. Rising from the floor of the western A Shau Valley, it is a looming, solitary massif, unconnected to the ridges of the surrounding Annamite range. It dominates the northern valley, towering some 937 metres above sea level. Snaking down from its highest peak are a series of ridges and fingers, one of the largest extending southeast to a height of 900 metres, another reaching south to a 916-meter peak. The entire mountain is a rugged, uninviting wilderness blanketed in double- and triple-canopy jungle, dense thickets of bamboo, and waist-high elephant grass. Local Montagnard tribesmen called Ap Bia "the mountain of the crouching beast."
In May 1969, Dong Ap Bia was the site of the Battle of Hamburger Hill.