The Romanians had constructed makeshift shelters at the site even though there was no running water or electricity, the London Evening Standard reported.
They assembled huts from waste wood, rubble and plastic taken from homes surrounding the suburban football ground.
Police, U.K. border agents and local council officials moved in to clear the area early Wednesday morning.
Twenty of the Romanians had agreed to accept flights home by mid-morning, witnesses said.
The rest were issued papers instructing them to leave but immigration officials said they could not enforce any deportations for at least 30 days.
Most of the squatters were men, officials said.