National Capital Botanical Gardens, Botanical garden in Port Moresby, Papua New Guinea.

The National Capital Botanical Gardens is a large space filled with tropical and rainforest plants arranged into separate themed sections. It contains over one thousand plant species from different families, each grouped according to their natural associations.

André Millar founded the gardens in 1971 on about 25 hectares near Port Moresby as a teaching garden for the University of Papua New Guinea's biology department and as a nursery supplying plants for university research. After Millar left at the end of 1971, the site fell into neglect and became overgrown scrub. In 1993 the National Capital District Commission took control and began a major reconstruction programme.

The garden's orchid collection is the core of its cultural work: more than 11,000 orchids, many native to Papua New Guinea, are grown in a large glasshouse, while a second glasshouse holds hybrids sold as cut flowers in the garden's own shop. A research centre with a herbarium and a tissue-culture laboratory raises thousands of orchids from seed each year.

The site is laid out with marked pathways that are easy to follow, with rest areas scattered throughout. It is best to visit early in the day when it is cooler and to wear comfortable walking shoes since exploring the gardens involves considerable walking.

The gardens maintain a herbarium with hundreds of preserved plant specimens that researchers use to study local vegetation. This collection supports scientific work and helps understand the characteristics of different plant species in the region.