The name 'Ratnapura' is a Sanskrit word meaning "city of gems", from the Sanskrit words pura (town) and ratna (gemstone). Over 2000 years ago, when the first Buddhist monks arrived here from the north eastern provinces of India namely Bodh-Gaya, Varanasi and Pataliputra, they not only brought with them the Buddhist religion, but since their teachings were mainly in Sanskrit and Pali they also influenced the local language. While candy produced from the jaggery palm is traditionally known in this region as ratnapura, it is more likely that the candy was named for the locale rather than vice versa.
It is the centre of a long-established industry of precious stone mining including rubies, sapphires, and other gems. Apart from gem mining, the city is known for the production of rice and fruit. Large plantations of tea and rubber surround the city. Tea grown in this region is called low-country tea. There is a well-established tourism industry in Ratnapura. Nearby Sinharaja Forest Reserve, Udawalawe National Park, Kitulgala, and Adam's Peak are especially popular among tourists.