The Viennese Sausage (German: Wiener Würstel) is a thin sausage in a sausage skin, and a modification of the original Frankfurter sausage.

The sausage is called "Viennese" in most of all parts of Germany and Switzerland ("Wienerli"). But in Austria and some other countries the sausage is called "Frankfurter", which sometimes leads to misunderstandings.

The sausage is known in Frankfurt/Main since the Middle Ages. The citizens there claim that also the Viennese sausage was invented in their city.

The official story is that a man called "Johann Georg Lahner", who lived from 1772 to 1845, moved from Frankfurt to Vienna in 1805, and became famous in Vienna with his Frankfurter sausages. During the 19th century the sausage became more and more popular, and reached nowdays its world success.