Royalp Tilsit or Swiss Tilsit is a light yellow semi-hard smear-ripened cheese made from unpasteurised/pasteurised cow milk. The pasteurised version is mild in flavour whereas the one made from fresh, unpasteurised milk is more strong in flavour (called Farmhouse Tilsit). It is aged for about 5 months, which makes it a very strong flavoured cheese comparable to a Limburger. The third version is made from pasteurised milk with added cream.

Tilsit displays a brownish-orange washed rind with a springy elastic semi-firm texture that is ideal for slicing. It is moist and creamy with spicy undertones. This cheese has a piquant flavour which makes it a perfect table cheese. It can be used in salads, added to sauces or melted over baked dishes.

There are various producers around the world who make Tilsit under their brand’s name. This includes the one made on Heidi farms in Tasmania, Australia, called 'Heidi Tilsit'.

Though the cheese was called Royalp Tilsit or Tilsiter in Switzerland during the olden days, it is now simply called Tilsiter or Tilsit. Outside of Switzerland, it is known by different names depending upon where it is produced. It is called Havarti Tilsit in Denmark, and Tilsiter or Tollenser in Germany.