DeCoursey is both a surname and a given name. Notable people with the name include:
Surname: James H. DeCoursey Jr. (1932-2016), American politician Jillian DeCoursey (born 1984), American mixed martial artist Patricia DeCoursey (1932–2022), American biologist Pete DeCoursey (1961–2014), American journalist
Given name: DeCoursey Fales (1888–1966), American bibliophile