The Kalderash are a subgroup of the Romani people. They were traditionally coppersmiths and metal workers and speak a number of Romani dialects grouped together under the term Kalderash Romani, a sub-group of Vlax Romani.

The Kalderash of the Balkans and Central Europe, in addition to the Gitanos and Manouche/Sinti, are seen as one of the three main confederations (Romani: natsiya) of Romani people in Europe by certain ethnographers. The Kalderash are recognized as the most numerous confederation of the three. Each main confederation is further split up into two or more subgroups (Romani: vitsa) based on a combination of factors such as occupation, ancestry, or territorial origin. Although originally referring to a specific vitsa of traditional coppersmiths, the name Kalderash is now applied to several Vlax-Speaking Roma groups. Because of this, significant differences in speech and culture can be seen in Western and Eastern Kalderash populations; as evidenced in the differences between the eastern Kalderash of Russia and the western Kalderash of Serbia. Certain scholars have suggested a connection between occupational Romani subgroups and the Caste System of India; with the Kalderash being described as an ancestral stock of the Lohar caste.

The name Kalderash (kalderash in Romani, căldărari in Romanian, kalderás in Hungarian, калдараш (kaldarash) in Bulgarian, kalderaš in Serbo-Croatian, 'котляри (Kotlyary) in Ukrainian, and кэлдэрары (kelderary) in Russian) is an occupational ethnonym which descends ultimately from the Romanian word căldăraș (coppersmith) derived from Latin caldāria, in effect describing their trade as tinkers.

The Kalderash Roma are hypothesized to originate in the territory of modern-day Romania and to have migrated to different parts of the world following the abolition of Slavery in Romania in the late 1800s in a phenomenon known as the great Kalderash migration. There are estimated to be about 200,000 Căldărari still living in Romania, although the exact number is unknown. The region of Dobruja is a major center of Kalderash settlement, as well as, Wallachia and the Romanian-Bulgarian border regions. Bilingualism of Kalderash Romani and Romanian is prevalent among the Kalderash of Romania. Traditional societal traits of the Kalderash of Romania include endogamy, cross-cousin marriage, and customary courts known as Kris in Southern Transylvania and Wallachia. As revealed by their traditional ethnonym of Căldărari, the Kalderash are associated with a tradition of artisans especially that of copper and tin smithing. The head of Kalderash communities in Romania is associated with a chief known as a Bulibasha that has varying degrees of authority based on their locality. The Kalderash of Romania are further broken down into many different subgroups(vitsi) such as the Pletoshi (Kalaydzii) and Chori (Grebenari, Pieptenari) in Northern Dobruja, as well as in Militari, Tasmanari and Zhaplesh, in Southern Dobruja. Intra-ethnic marriages have united various subgroups such as Grastari, Niculešti, Dudulani, Tasmanari, Žapleš, Lajneš, Njamcurja under a common Kalderash identity.

The Kalderash are one of the 5 main Romani subgroups living in Bulgaria along with the Daskane Roma, Horahane Roma, Kalaydji, and Boyash. During the 18th and especially during the 19th centuries following the abolition of Slavery in Romania, Roma from the Romanian principalities of Wallachia and Moldavia entered the Bulgarian territory in an event coined by certain ethnographers as the "Kalderash Invasion." In addition, a large part of the Kalderash migrated from Romania to Bulgaria through the Austro-Hungarian Empire passing through Serbia before finally reaching Bulgaria. The Kalderash are the second largest Romani confederation in Bulgaria and are split up into 2 main subgroups: the Lovari and Kalaydji, as well as, further branches within these subgroups such as "Grebenari", "Bakarjii", "Reshetari", etc. The Kalderash of Bulgaria mostly practice Eastern Orthodox Christianity and are bilingual in Kalderash Romani and Bulgarian. The customary courts of the Bulgarian Kalderash are known as the meshere.

The Chergashe Roma are a primarily Kalderash subgroup living mostly in Serbia and Bosnia and Herzegovina. During the late 19th century, large migrations of the former Kalderash slaves of Romania to the neighboring countries of Serbia and then Bosnia occurred. They speak Kalderash Romani and are mostly concentrated around Banja Luca and Sarajevo. Since the dissolution of Yugoslavia, many Serbian and Bosnian Kalderash have immigrated to the United Kingdom to escape the economic and social oppression that Balkan Roma face in their home countries.

The Kalderash Roma are one of the most populous Romani groups in Russia following the Ruska Roma. The Kalderash migrated from the territory of the Romanian principalities and other parts of Southeast Europe to Russia and Ukraine between the end of the 19th and the first 30 years of the 20th century following the abolition of Slavery in Romania. They spread throughout Ukraine and Russia migrating from Bessarabia to the north and east. They soon became a relatively numerous group in Russia and their traditional occupations of tinning and cauldron making led them to initial prosperity. At the end of the 1920s and the beginning of the 1930s, the state took on a policy of industrialization that aimed at bringing a settled way of life to the nomadic Kalderash Roma. This resulted in the Kalderash becoming actively involved in cooperatives and establishing their own Romani production cooperatives called artels. These industrial artels helped the Kalderash successfully adapt their traditional craft to the new economic reality of the Soviet Union. The artels lasted until the 1980s and became a vibrant part of the oral history of the Kalderash families. During the artel period, most Kalderash camps were located in Moscow, however, after the dissolution of the artels, the Kalderash migrated all over Russia and other parts of Northern Europe. The Kalderash of Russia are mostly bilingual in Kalderash Romani and Russian.

In France, the Kalderash Roma are concentrated in the eastern suburbs of Paris. It is estimated that they have been gradually settling there since at least the 1940s. Montreuil is a town in the fringe of Paris with the largest Kalderash settlement in France. The Kalderash of Montreuil first arrived in France in 1941 following the German occupation of Paris. They still practice their traditional trade as coppersmiths and metal workers. Some Kalderash still travel around the French provinces although most are now sedentary. Despite frequent contact with non-Roma throughout their daily lives and economic activity, the Kalderash have managed to keep a degree of invisibility within French society that allows them to practice their traditional culture without fear of assimilation. In 2005, there was estimated to be about 8,000 Kalderash Roma living in France.