Pleurothallis is a genus of orchids commonly called bonnet orchids. The genus name is derived from the Greek word pleurothallos, meaning "riblike branches". This refers to the rib-like stems of many species. The genus is often abbreviated as "Pths" in horticultural trade.

Orchids are plants that belong to the family Orchidaceae, a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Orchids are cosmopolitan plants that are found in almost every habitat on Earth except glaciers. The world's richest diversity of orchid genera and species is found in the tropics.