It is endemic to Papua, Western New Guinea, and only known from its type locality in the Derewo River basin, in the mountains to the southeast of Cenderawasih Bay.

[2] Adult males in the type series measure 9.2–11.5 mm (0.4–0.5 in) in snout–vent length; females are unknown.

The dorsum has scattered low tubercles forming an hourglass pattern.

[2] Oreophryne minuta is known from montane tropical rainforest at about 2,000 m (6,600 ft) above sea level.

They were calling at night from within thick clumps of moss that covered the boulders and low tree branches, none higher than 2 m (7 ft) above the ground.