A 2008 AP file photo of Matt Damon, left, and Ben Affleck.
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 US from England in the 1630s and settled in Ipswich.
The society said that Affleck has lots of other famous relatives, including 16 US 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.
