Barack Obama and Dick Cheney (and Brad Pitt) are not the only people who have odd common ancestry.

John McCain’s vice-presidential running mate, Sarah Palin, is linked in her family tree to former U.S. President Franklin Roosevelt and the much-beloved Princess Diana.

According to genealogists at Ancestry.com, Roosevelt, the Depression-era Democratic president, is Palin’s ninth cousin once removed. Their common ancestor is Puritan Presbyterian Rev. John Lothrop, who came from England to Massachusetts in 1634.

The website also says the Alaska governor is a tenth cousin of the late British royal, Princess Diana.

Palin and Diana descended from John Strong and his wife Abigail Ford. Strong was born around 1605 in England and emigrated to the United States, where he died in Massachusetts in 1699, Ancestry.com said.

Cheney’s wife, Lynne, last year uncovered ancestral ties – eighth or ninth cousins once removed, depending on who you talk to - between her husband and Obama while researching her book.

Obama, the Democratic presidential hopeful and Illinois senator, is also a ninth cousin of actor Brad Pitt. Ancestry.com says: "Obama and Pitt are ninth cousins, sharing an eighth great–grandfather named Edwin Hickman. Hickman owned land in Virginia that was eventually purchased by Thomas Jefferson and incorporated into Monticello."

"When you’ve got candidates who have deep roots in America, there’s a good chance that they’re going to have some famous cousins," Ancestry.com’s chief family historian, Megan Smolenyak, told Reuters. "We’ve all got literally millions of cousins. The trick is finding that one little connection that results in something like Sarah Palin being related to FDR or Diana.”