He was appointed Saturday in Rwanda's capital as a U.N. Environment Program Goodwill Ambassador and vowed to fight climate change and promote environment conservation.
UNEP Executive Director Achim Steiner announced the appointment, saying that Cheadle would help raise green awareness among millions of people around the globe.
Cheadle also named a baby gorilla Zoya, a name chosen by internet users as part of a UNEP awareness program.
In 2004, Cheadle starred in the film "Hotel Rwanda" which told the world about the Rwandan genocide in 1994 that claimed the lives of more than 500,000 people, mostly Tutsis and moderate Hutus. The Rwandan government, however, was critical of the film.