Of the four major counties in Southeastern Michigan, both Oakland and Washtenaw counties had the highest percentage of foreign-born populations in 2015, according to the American Community Survey. Oakland County ranked just above Washtenaw County though; the foreign born population percentage in Oakland County was 11.8 percent and in Washtenaw County it was 11.6 percent. In Oakland County there are three municipalities where more than 20.1 percent of the population was foreign born in 2015, while in Oakland County there was only one municipality.

Of all the municipalities in the region though it was Hamtramck with the highest percentage of foreign-born residents at 46.6 percent.

The U.S. Census Bureau defines a foreign-born person as “anyone who was not a U.S. citizen at birth. This includes respondents who indicated they were a U.S. citizen by naturalization or not a U.S. citizen. Persons born abroad of American parents or born in Puerto Rico or other U.S. Island Areas are not considered foreign born.”

In Macomb County in 2015, 10.6 percent of the population was foreign-born, with the city of Sterling Heights having the largest foreign-born population. In Sterling Heights 25.8 percent of the population was foreign-born; this is equivalent to 33,598 people in the city. Of those residents, 58.7 percent were naturalized U.S. citizens and the remainder (41.7%) were not U.S. citizens.

Aside from Sterling Heights, Warren and Shelby Township had amongst the highest foreign-born populations at 12.1 percent and 13.5 percent, respectively.

All of northern and eastern Macomb County had less than 5 percent foreign-born populations.

In Oakland County, it was the western side of the county where majority of the municipalities had less than 5 percent of their populations made up of foreign-born residents. The city of Troy had the highest percentage of foreign-born residents in Oakland County at 25.8 percent, followed by West Bloomfield Township at 20.9 percent and Novi at 20.8 percent.

In Troy, 52 percent of the foreign-born residents were naturalized U.S. citizens and the remainder were not U.S. citizens. Between Troy, Novi and West Bloomfield Township, Novi had the highest percentage of non-U.S. citizens at 55 percent.

In Washtenaw County, Ann Arbor Township had the highest percentage foreign-born residents at 21.8 percent. This percentage was the equivalent to about 971 people in the charter township. Of these people, 49 percent were naturalized U.S. citizens and the remainder were not U.S. citizens. The city of Ann Arbor and Pittsfield Township followed Ann Arbor Township in terms of foreign-born populations. The percentage of foreign-born residents residing in Ann Arbor was 17.9 percent and in Pittsfield Township was 18. percent. These percentages were equivalent to 20,762 foreign-born residents in Ann Arbor and 6,753 in Pittsfield Township.

In Wayne County, Dearborn and Hamtramck had the highest percentage of foreign-born residents at 26.4 percent and 46.6 percent, respectively. In Dearborn, of the 25,410 foreign-born residents 65 percent were naturalized citizens. In Hamtramck, of the 9,589 foreign-born residents, 45 were naturalized U.S. residents.

In Detroit, the foreign-born population made up about 37,000 residents but was equivalent to 5.1 percent of the population.