The number of people living in the West Midlands born outside the UK has risen by 180,000 - or nearly two thirds - in a decade.
Data released by the Office for National Statistics today showed there were an estimated 474,000 foreign-born residents in metropolitan county in 2014.
They now make up 17.1 per cent of the total population of 2.8 million.
Put another way, around one person in six in the West Midlands was born outside the UK.
As recently as 2004, there were an estimated 294,000 non-UK-born citizens out of a total population of 2.6 million.
At that point, foreign-born citizens made up 11.4 per cent, or roughly one in nine, of all people living in the West Midlands.
In Birmingham, an estimated 20.3 per cent of people - 222,000 out of a total population of 1.1 million - were born abroad.
That compares to 159,000 out of 992,000, or 16 per cent, a decade earlier.
It means roughly one person in five currently living in the city was born outside the UK.
In Coventry, the proportion of foreign-born residents rose from 14.5 per cent in 2004 to 23.6 per cent - nearly one in four - in 2014.
There are currently an estimated 78,000 people living in Coventry who were born outside the UK, compared to 43,000 a decade earlier.
In Sandwell, an estimated 62,000 of the 2014 population were born abroad. That figure stood at 27,000 in 2004.
Wolverhampton has seen a rise from 29,000 to 46,000, Dudley from 9,000 to 16,000, Solihull from 11,000 to 22,000 and Walsall from 16,000 to 29,000.
The figures are estimates and not based on exact counts of everyone in the local area.
The figures were released on the same day data showed net migration had hit a record high of 330,000 in the 12 months to March.
Across the UK as a whole, the number of foreign-born people living in the country has risen above eight million for the first time.
A total of 14.2 per cent of the population of England in 2014 were born abroad, compared to 9.9 per cent in 2004.