Almost 10,000 foreign-born residents live in Boston, according to the latest batch of 2011 Census data.
The borough has been held up in the national press as an example of rapid population change since 2001, with the number of residents born overseas rising from fewer than 1,500.
The statistics show that Boston has more Polish residents than anywhere outside of the south east, with 3,000 living in the borough.
The information, the second round of data released, shows 12.1 per cent of Boston residents hold non-British EU passports - well above the Lincolnshire average of 3.5 per cent.
In total 15.2 per cent of people in Boston were born abroad.
The borough council launched an inquiry earlier this year to look at how to tackle the impact of rapid population growth – but protesters believe they have not done enough and held an anti-immigration demonstration in the town last month.
Other information from the census shows a big drop in the number of people in Boston describing themselves as Christian, with the figure falling from 80.2 per cent in 2001 to 71.1 per cent in 2011.
The number of people with a mortgage dropped from 35.6 per cent to 30 per cent.