The Short Version
No U.S. president has ever identified as Muslim, and the historical record is unambiguous on this point. The National Archives, Pew Research Center, and multiple independent fact-checkers confirm that all 47 presidents have been Christian or deist. The most common basis for this claim — that Barack Obama was Muslim — has been thoroughly and repeatedly debunked by the very sources sometimes cited to support it. Public rumors and the absence of a constitutional religious test do not constitute evidence that a Muslim president has served.