Oda Helen Sletnes (born 10 February 1953) is a Norwegian diplomat.

She was born in Trondheim, and studied architecture at the Norwegian Institute of Technology.

She started working for the Norwegian Ministry of Foreign Affairs in 1981.

After a period as deputy under-secretary of state in the Ministry of Foreign Affairs from 2003 to 2006, she was the Norwegian ambassador to the European Union from 2006 to 2011.

In 2011 she was appointed as a college president of the European Free Trade Association Surveillance Authority, a position she held until 2015.