Niède Guidon (Portuguese pronunciation: [niˈɛdʒi ɡiˈdõ]) (born 12 March 1933) is a Brazilian archaeologist known for her work in pre-historic archeology of South American civilizations and her efforts to secure the conservation of the World Heritage Site Serra da Capivara National Park.

Educated in Brazil and France, she worked in Paris for most of her career. She was the founding president of the Fundação Museu do Homem Americano (American Man Museum Foundation), a non-profit organization created to support the Serra da Capivara National Park, a World Heritage Site. In 2005, she was one of the 1000 women nominated for the Nobel Peace Prize.

Since the early 1970s, Guidon has conducted archeological research in Southeast Piauí, where thousands of archeological sites have been discovered. Her dates from those sites indicate that human settlement preceded North America's Clovis people by tens of thousands of years. In the late 1980s, these findings challenged the mainstream theory of Clovis First and have generated debate in the academic archeology community.

Guidon has won several national and international awards, including the Prince Claus Award, and the Ford conservation and Environment award.