Ruth Metzler-Arnold (born 23 May 1964) is a Swiss politician and former member of the Swiss Federal Council (1999-2003).
She was elected to the Swiss Federal Council on 11 March 1999, as a member of the Christian Democratic People's Party from the Canton of Appenzell Innerrhoden. During her time in office she headed the Federal Department of Justice and Police. She won 14 referendums during her time in office.
On 10 December 2003, she became the third member of the council not to be reelected in the history of the Swiss Federal State. In the 2003 Federal Assembly elections, her party lost many voters and the Swiss People's Party became the largest party of Switzerland. The Swiss People's party then requested another seat in the Federal Council. In the elections for the Federal Council on 10 December, the Federal Assembly did not re-elect Ruth Metzler and elected Christoph Blocher instead, by 121 votes to 116 on the third round of voting. She challenged her CVP colleague Joseph Deiss for his seat, but lost by 138 to 96. Metzler kept her seat until the end of the year and Christoph Blocher succeeded her on 1 January 2004.
She published the memories of those years under the title "Grissini & Alpenbitter", 2004, ISBN 3-85882-388-0.
She was teaching between February 2004 and July 2004 at the University of St. Gallen a class called "Gestaltungsmöglichkeiten in der Politik" which can be translated as "scope for design in politics". Since April 2005 she has been working for the Swiss pharmaceutical company Novartis.