The Israeli ambassador to the U.S. is Ron Dermer, who was born American and is now an Israeli citizen.
According to Wikipedia, Ron Dermer is an American-born Israeli diplomat and political consultant who currently serves as the Israeli Ambassador to the United States.
“He previously served as Israel’s economic envoy to the United States from 2005 to 2008, a position requiring him to give up his American citizenship, and subsequently served as senior advisor to current Israeli Prime Minister Benjamin Netanyahu for four years. On July 9, 2013 Dermer was confirmed as Israel’s ambassador in Washington, replacing Michael Oren.”
His U.S. party affiliation is unclear – he has been described as a “GOP activist,” but his father and brother were Democrats.
According to the New York Times, the White House is furious with Israeli ambassador Ron Dermer for helping John Boehner coordinate Israeli Prime Minister Benjamin Netanyahu’s March visit to congress, all behind the Obama administration’s back. In some ways, the legality of the situation is in question.