One of Singapore's best-known watercolourists, Ong Kim Seng learnt by observing pioneer watercolourists who painted by the Singapore River. The mouth of the river used to be the port of Singapore which had been the centre of commercial activities and is linked to the country's history and social culture. Self-taught Ong Kim Seng has travelled all over the world to paint quaint scenes of romance. Such is his skills that he is the first Asian outside of the United States to be made a member of the American Watercolour Society, and after winning a total of six different awards made a Dolphin Fellow in 2000 (he is a member since 1992). In Singapore, he was accorded the Cultural Medallion (1990) and the Arts Supporters Award (2001) for being adviser to the National Arts Council since 1998. He is also president of the Singapore Watercolour Society from 1991 to 2001, and organising chairman of the Asian Watercolours 1997. His collectors include Queen Elizabeth II, former UN secretary-general Kofi Anan, and former prime ministers of Thailand, Japan and India. In the Hong Kong Sotheby's auction on April 2, 2017, his acrylic on canvas, Nepal, sold for a premium of HK$735,000.