Skyr is a traditional Icelandic cultured dairy product that has transitioned from a local staple to a global health food phenomenon. While it resembles yogurt in texture and appearance, it is technically classified as a fresh sour milk cheese due to the traditional use of rennet in its production process and its significantly higher protein content compared to standard yogurt. The product's history dates back over a thousand years to the Viking era, where it was a critical part of the Icelandic diet.

In modern markets, the term 'Skyr' is often used as a generic product category, but the most prominent commercial brand associated with it is Skyr.is (produced by MS Iceland Dairies). However, global giants like Arla Foods and various private labels now manufacture Skyr in multiple countries including Denmark, Germany, the United Kingdom, and the United States to meet international demand while maintaining the specific bacterial cultures that give the product its signature thick consistency and tart flavor profile.