Roaring Billy Falls is a waterfall in Mount Aspiring National Park, Westland District, New Zealand.

[3] A viewing point is accessible via a one-kilometre-return (0.62 mi) walkway from the carpark on State Highway 6.

[4] The path to the viewing point passes through forest on a fertile alluvial terrace with a wide diversity of rainforest plants.

[5] The canopy consists of silver beech (Nothofagus menziesii), southern rātā (Metrosideros umbellata) and kāmahi (Weinmannia racemosa), and a wide range of podocarps including miro (Prumnopitys ferruginea), mataī (Prumnopitys taxifolia), kahikitea (Dacrycarpus dacrydioides), rimu (Dacrydium cupressinum) and Hall's tōtara (Podocarpus laetus).

Beneath the canopy there is māhoe (Melicytus ramiflorus), patē (Schefflera digitata), mountain horopito (Pseudowintera colorata), wineberry (Aristotelia serrata), tree fuchsia (Fuchsia excorticata) and Coprosma rotundifolia.