Walser German (German: Walserdeutsch) and Walliser German (Walliserdeutsch, locally Wallisertiitsch) are a group of Highest Alemannic dialects spoken in parts of Switzerland (Valais, Ticino, Grisons), Italy (Piedmont, Aosta Valley), Liechtenstein (Triesenberg, Planken), and Austria (Vorarlberg).

Usage of the terms Walser and Walliser has come to reflect a difference of geography, rather than language. The term Walser refers to those speakers whose ancestors migrated into other Alpine valleys in medieval times, whereas Walliser refers only to a speaker from Upper Valais – that is, the upper Rhone valley. In a series of migrations during the Late Middle Ages, people migrated out of the Upper Valais, across the higher valleys of the Alps.

The Alemannic immigration to the Rhone valley started in the 8th century. There were presumably two different immigration routes, from what is now the Bernese Oberland, that led to two main groups of Walliser dialects. In the 12th or 13th century, the Walliser began to settle other parts of the Alps. These new settlements are known as Walser migration. In many of these settlements, people still speak Walser.

Because the people who speak Walser German live in the isolated valleys of the high mountains, Walser German has preserved certain archaisms retained from Old High German which were lost in other variants of German. The dialect of the Lötschental, for instance, preserved three distinct classes of weak verbs until the beginning of the 20th century.^{[clarification needed]}

Walser German dialects are considered endangered, and language shift to the majority language (French, Italian, Standard German) has taken place in the course of the later 20th century.

Walser German is part of the Highest Alemannic group, most closely related to dialects spoken in the Bernese Oberland and in Central Switzerland (Uri, Schwyz, Unterwalden, Glarus).^{[citation needed]}

There is limited mutual intelligibility with High Alemannic forms of Swiss German (whose speakers are called Üsserschwyzer "outer Swiss" by the Walliser), and barely any mutual intelligibility with Standard German.^{[citation needed]}

In Italy, Walser German is almost never spoken among children of Walser people and is rarely spoken by their parents and most commonly by the grandparents. Often, older people will speak to younger people in Walser German, with the younger people responding in Italian. Walser German is most commonly but not exclusively used in private and familial settings when no non-speakers are present.