The article overviews the history of two religious groups which have been significant among Russian migrants to Norway: Orthodox Christians and the Jews. They are described in detail in microdata from the nominative censuses of 1865, 1875, 1900, and 1910, which are used for both qualitative and quantitative purposes. The aggregates from other censuses during the period between 1845 and 1960 are employed more summarily. Together with Canada, Norway has the world's longest history of censuses with religious affiliation as a variable. The number of Orthodox Sami peaked in the second half of the 19th century, but declined together with the number of persons classified as Sami thereafter. Traditionally the Orthodox Christian 'Skolt' Sami in the northeast worked as reindeer herders. Further south, we regularly find Orthodox Christians who were ethnic Russians employed as saw sharpeners. In the 20th century, the number of Orthodox Christians increased in southern Norway, especially in the Oslo area, where they organised their own congregation in 1931; their numbers peaked in 1960. In addition to Orthodox Christians, the article overviews the establishment and growth of a Russian Jewish community in Norway. Because of a prohibition in the 1814 Constitution, the Jews were not allowed to migrate to Norway until 1851, so they were only a handful of them according to the 1865 and 1875 censuses. However, from 1891, Jewish immigrants made up a significant and growing element of the population, which can be explained by their emigration from the western parts of the Russian Empire due to pogroms. Most men were employed in trade, although some of them were also itinerant. Thus, Russian religiosity in Norway, which started as a predominantly rural phenomenon in the north, became more important in southern Norway over time. However, the Norwegian State Church maintained its strong traditional position, with 96 per cent of the population being members in 1960.