Landammann

Landammann, is the German title used by the chief magistrate in certain cantons of Switzerland and at times featured in the head of state's style at the confederal level.
Landammann is also the official title of the mayor of Davos.

Old Swiss Confederacy

Landammann or Ammann was the elected judge and leader of the Landsgemeinde.
The term existed in the high medieval period, and was continued in the Old Swiss Confederacy of the 14th to 18th centuries.

Napoleonic period

While before and after other titles, generally expressing precedence, were used, the title of the Head of State of the Swiss Confederation has been:

Erster Landammann / Premier Landamman 'First official of the country': 23 November 1801 - 6 February 1802 Aloys Reding von Biberegg ; he succeeded himself as the first under the new, shorter, non-distinctive title:
Landammänner/ Landammans:
*6 February 1802 - 20 April 1802 Aloys Reding von Biberegg
*20 April 1802 - 5 July 1802 Vinzenz Rüttimann
*5 July 1802 - 8 March 1803 Johann Rudolf Dolder
*August 1802 - September 1802 Aloys Reding von Biberegg
under French occupation, when emperor Napoleon I Bonaparte styled himself 'Mediator' of the Swiss Confederation, the actual Head of the Confederation was simply the chief magistrate of the canton hosting the Swiss Diet, with the title Landammann der Schweiz / Landamman de la Suisse / Landamano della Svizzera, usually for a year, 10 March 1803 - 31 December 1813
Louis d’Affry, 10 March – 31 December 1803
Niklaus Rudolf von Wattenwyl, 1804
Peter Glutz-Ruchti, 1805
Andreas Merian, 1806
Hans von Reinhard, 1807
Vinzenz Rüttimann, 1808
Louis d’Affry, 1809
Niklaus Rudolf von Wattenwyl, 1810
Heinrich Daniel Balthasar Grimm von Wartenfels, 1811
Peter Burckhardt, 1812
Hans von Reinhard, 1813

Contemporary Switzerland

If the office is held by a woman, she is addressed as Frau Landammann. The French version is Landamman, the Italian Landamano.
Today, Landammann still is the title of the president of the cantonal executive in the following Swiss cantons :

Some Swiss towns in those cantons use the equivalent title Stadtammann for the mayor.