Mr Jack Sim, who has been dubbed Singapore's Mr Toilet, was among 17 social change-makers honoured on Sunday at an international summit supported by the United Nations (UN).
The World Toilet Organisation (WTO) founder was the only Singaporean recognised at the Novus Summit, which was held in New York City at the UN General Assembly Hall.
Mr Sim, 59, was among luminaries such as Ms Anousheh Ansari, the first female private space explorer, UN Women deputy executive director Lakshmi Puri and Mr Matthew Bishop, US business editor and New York bureau chief of The Economist news magazine.
The summit, held in partnership with the UN Department of Economic and Social Affairs, was in conjunction with the UN High Level Political Forum for Sustainable Development.
It was meant to bring together humanitarians and innovators to promote the UN's sustainable development goals.
Mr Sim said: "I never expected to receive an award next to people of such rank.
"It feels good but, of course, any prize is only for the sake of gaining recognition for the mission and normalising the taboo of toilet sanitation."
He founded the World Toilet Organisation in 2001 to campaign for better sanitation standards in toilets worldwide.
The former businessman made his mark on the world map in 2013, when the United Nations General Assembly agreed to adopt a resolution to mark Nov 19 as World Toilet Day, after he suggested this to the Ministry of Foreign Affairs about four years earlier.
On that day last November, he started a World Toilet College in India to educate locals on toilet cleaning and maintenance, and the importance of good hygiene.
Mr Sim is also working with the Andhra Pradesh state government to build six million toilets there.
In 2008, he was recognised as Time magazine's Hero of the Environment.