The Dolmen of Oppagne, also known as the southern dolmen or Wéris II is a portal grave (allée couverte) attributed to the Seine-Oise-Marne culture. The dolmen is located near Wéris in the territory of the village of Oppagne in the Belgian province Luxembourg. The dolmen is located in the fields about a kilometre southwest of the village.

In the area, to the north-east, about 1.5 km away there is another larger and better-known dolmen: the Dolmen of Wéris and in and around the valley in which Wéris is located, there are a number of menhirs. The different megaliths in the environment would form different alignments that are parallel to each other. The dolmen is believed to have been constructed 5000 years ago during the late Neolithic period.

The dolmen of Oppagne was discovered in 1888, when a young man decided to excavate and relocate the large stones in the field, which made plowing difficult. During this process, he discovered that the stones were part of a dolmen. It was then revealed that three menhirs were also located near the dolmen.