According to the New England Genealogical Society, they're also cousins. Tenth cousins, once removed, that is.
Society researchers dug up evidence that both Damon and Affleck are descended from William Knowlton Jr. He was a bricklayer who came to the U.S. from England in the 1630s and settled in Ipswich.
The society said Friday that Affleck has lots of other famous relatives, including 16 U.S. presidents _ Barack Obama among them _ and the late Princess Diana.
Affleck and Damon were friends growing up in the Boston area and teamed up as writers and co-stars for the 1997 film "Good Will Hunting."
On the Net:
New England Historic Genealogical Society: http://www.newenglandancestors.org