Using mobile network operator data, the study analyzes the modern ethnic landscape of the Moscow agglomeration formed by foreign migrants. Their total number and monthly dynamics from October 2021 to October 2022 were analyzed. Foreigners’ main areas of residence were identified, the ethnic diversity of municipalities was assessed, and the main types of settlement pattern of national-ethnic communities were identified. The study showed that the total number of foreign migrants in the agglomeration reaches 1.8 mln people, or 9% of the total population, remaining almost unchanged against the backdrop of the events of 2022, including the special military operation. The share of foreigners is minimal in closed administrative-territorial units (below 3%), and it is also small in the remote parts of Moscow Region, as well as in expensive areas of the capital. At the same time, eight municipalities in the agglomeration have crossed the 17% mark, the so-called tipping point, reflecting a sharp increase in the risks of interethnic conflicts and ghettoization of the urban space. The two most noticeable areas of increased concentration of foreign migrants have been identified in the southeast at the junction of Moscow and Moscow oblast (Lublino–Kotelniki) and in New Moscow (Mosrentgen–Sosenskoe). Calculation of the Ekkel’ ethnic mosaic index has confirmed the presence of pronounced interethnic contact zones here. Elevated index values were also noted in most areas of the center and southwest of the capital, which, with a lower share of foreign residents, is associated with a high density of office buildings, diplomatic institutions, and universities. Analysis of the settlement patterns of national-ethnic groups of migrants revealed three types determined in accordance with the adaptive capabilities of ethnic communities. A diffuse, relatively uniform settlement pattern is characteristic of both the largest ethnic groups (citizens of Tajikistan, Uzbekistan, and Kyrgyzstan) and those most culturally close to the local population (immigrants from Ukraine and Belarus). A concentric settlement pattern (in residential areas of Moscow and satellite cities) is typical of relatively large ethnic groups from post-Soviet countries (citizens of Azerbaijan, Armenia, and Georgia). The local type is characteristic of small ethnic communities that gravitate towards certain areas of the capital.