Pierogi are a kind of dumpling also known as perogi, perogy, piroghi, pirogi, or pyrohy. Most English-speakers treat these forms as singular and form the plural by adding -s, but a few consider them plural and form the singular by removal of the -i or -y. In Swedish however, the singular form is pirog and the plural form is created by adding -er at the end. Pierogi is the plural form of the Polish pieróg.


Pierogi are of virtually untraceable Central or Eastern European origin; claims have been staked by the Poles, Russians, Lithuanians, Ukrainians, Rusyns, Slovaks, and the Czechs. Similarity to dumplings found in the Far East such as Chinese potstickers fuels speculation, well-founded or not, that the Mongols and Tatars brought the recipe to the West.
Pierogi are crescent-shaped dumplings of unleavened dough, stuffed with sauerkraut, cheese, mashed potatoes, cabbage, onion, meat, hard-boiled eggs (the last is rather Mennonite-specific), or any combination thereof, or with a fruit filling. They are typically fried or boiled until they float, and then covered with butter or oil; alternatives include the Mennonite tradition of baking and serving with borscht, and the Polish way of boiling, then frying in butter, and serving topped with bread crumbs. They are typically served with plenty of sour cream, and the savoury ones are topped with fried bacon or onions. The most popular of the Polish variety are savoury pierogi ruskie, stuffed with cheese, mashed potatoes, and onion. Meat-filled, boiled dumplings called pelmeni (пельмени), originating in Siberia, are very popular throughout Russia and in other parts of the former Soviet Union.
In the United States, the term Pierogi is commonly taken to mean Polish pierogi. The word pirog (or its equivalent in the various Slavic languages) means pie, which can take the form of a stuffed dumpling, pastry, or two-crusted pie. Varenyky or vareniki are boiled pierogi (from varyt', "to boil") and are particularly Ukrainian. In Russian, pirogi is the plural form of the generic pirog, which usually refers to a large double-crust pie and not a dumpling (pelmeni or vareniki) or filled bun (pirozhki).
In Russian cuisine, pirozhki (also piroshki, or Ukrainian pyrizhky) are small stuffed buns made of either yeast dough or short pastry. They are filled with one of many different fillings, and either baked or fried. The singular form is pirozhok, the diminutive form of the word pirog. The stress in pirozhki is properly placed on the last syllable: [piroʒˈki].
In Hungarian cuisine, the pierogi is used as primarily as a festive food for special occasions such as weddings. It was brought to Hungary by the merchant Andras Perl, for his wedding with his wife Katalin in 1764. The Banki family, home to Katalin, usually renowned for its ferocity in battle, was so moved by the pierogi that now, pierogi are common at most Hungarian weddings.
Pierogi are popular throughout Russia, Central Europe, and Eastern Europe, including Greece, and in areas of North America where immigrants brought their cuisine. Pierogi at first were a family food among immigrants, but in the post-World War II era, freshly cooked pierogi became a staple of fundraisers by ethnic churches. By the 1960s, pierogi were a common supermarket item in the frozen food aisles in parts of the United States and Canada. The Canadian Prairies in particular have a large Ukrainian population, and pierogi (usually called perogy, -ogies [pəˈroːgi]) are very common in restaurants and supermarkets, and so familiar that some Asian restaurants bill their pot-stickers as "Chinese perogies". Ukrainian-speakers call them pyrohy, which can be misheard pedaheh by anglophones unaccustomed to the fast rolled-r sound, or alveolar tap.
Packed frozen pierogi can be found everywhere Russian or Polish communities exist. Such pierogi are made by industrial machines, often built by Italian companies such as Arienti & Cattaneo, Ima, Ostoni, Zamboni, etc. These pierogi usually weigh around 20 grams each but resemble an oversize half-moon ravioli, which is why Italian pasta machines are commonly used for industrial production.
In 1993, the village of Glendon, Alberta, Canada, unveiled its roadside tribute to this culinary treat: a 25-foot (7.6 m) perogy, complete with fork.