According to the first data for a full calendar year since the Brexit vote an estimated 101,000 more people arrived in the UK from the bloc than left in 2017.
It is the lowest for any 12-month period since the year to March 2013, when it stood at 95,000.
Overall net long-term migration, including arrivals and departures of non-EU nationals, was about 282,000 in 2017.
The figure was up by 33,000 on the year before, but statisticians attributed the rise to an “unusual pattern” in estimates of non-EU student immigration for 2016 which research indicates was an “anomaly”.
Nicola White, of the ONS’s Migration Statistics Division, said: “With around 280,000 more people coming to the UK than leaving in 2017, these latest figures show that migration has continued to add to the UK population.
“Net migration fell following record levels in 2015 and early 2016 and has been broadly stable since. This is similar to the level recorded in the year ending September 2014.
“Underlying this, immigration has remained broadly stable at around 630,000 and emigration has shown a gradual increase since 2015 and is currently at around 350,000.”