Maechidius dendrolagus is a species of beetle of the family Scarabaeidae. It is found in Papua New Guinea, where it occurs in lowland rainforests at about 750 meters altitude.
Adults reach a length of about 8-8.45 mm. They have the general features of the pauxillus species-group. The dorsal surface is opaque except on the anterior and lateral margins of labroclypeus.
The species is named after Dendrolagus, an enigmatic genus of marsupial endemic to New Guinea, adjacent islands and Australian Queensland.