The present study provides a comprehensive account of the orchid flora of Nainital, located in the western Himalayas, encompassing 44 genera and over 80 species. The surveyed taxa include epiphytic, terrestrial, and lithophytic forms, reflecting the region’s heterogeneous topography and microclimatic variability. Morphological analyses reveal considerable diversity in vegetative and reproductive structures, including specialized leaves, tubers, spurs, and lip morphologies, indicative of adaptive strategies for pollination and survival in contrasting ecological niches. Flowering periods extend from April to November, with species exhibiting staggered phenology, likely reducing interspecific competition and enhancing reproductive success. Several taxa, such as Vanda tessellata, Phalaenopsis taenialis, and Satyrium nepalense, are rare or locally restricted, emphasizing the vulnerability of these species to anthropogenic pressures, habitat fragmentation, and climatic fluctuations. The study further highlights Nainital as a significant biodiversity hotspot for Himalayan orchids, with notable biogeographical affinities spanning tropical and temperate Asia. The inventory, supplemented by detailed morphological descriptions, provides a valuable baseline for taxonomic verification, ecological assessment, and conservation planning. The findings underscore the urgent need for in situ conservation, habitat management, and ex situ propagation to safeguard the region’s orchid diversity. This work contributes to a deeper understanding of species distribution patterns, ecological requirements, and floristic richness, serving as a reference for future research and biodiversity monitoring initiatives in the Himalayan region.