A crayfish party is a traditional summertime eating and drinking celebration in the Nordic countries. The tradition originated in Sweden, where a crayfish party is called a kräftskiva. The tradition has also spread to Finland via its Swedish-speaking population.

Crayfish parties are generally held during August, a tradition that started because crayfish harvesting in Sweden was, for most of the 20th century, legally limited to late summer. Today, the kräftpremiär date in early August has no legal significance. Dining is traditionally outdoors, but in practice the party is often driven indoors by bad weather or aggressive mosquitoes. Customary party accessories are comical paper hats, paper tablecloths, paper lanterns (often depicting the Man in the Moon), and bibs.^[ A rowdy atmosphere prevails amid noisy eating and traditional drinking songs (snapsvisa). The alcohol consumption is often high, especially when compared to the amount of food actually eaten. It is considered customary to suck the juice out of the crayfish before shelling it.

Man in the Moon Decoration

Akvavit and other kinds of snaps are served, as well as beer. The crayfish are boiled in salt water and seasoned with fresh dill – preferably "crown dill" harvested after the plant has flowered – then served cold and eaten with one’s fingers.