Robert Holton Ziegler, Sr. (March 27, 1921 – September 29, 1991) was an American lawyer and politician.
Born in Baltimore, Maryland, Ziegler served in the United States Army Medical Corps during World War II.
From 1957 until 1959, Ziegler served in the Alaska Territorial House of Representatives and was a Democrat.
He owned the Ziegler House (Ketchikan, Alaska).
Ziegler died of cancer in Ketchikan, Alaska.