New research for the Centre for Cities shows that Sheffield exports 5 times as much to the EU as it does to the US, and 28 times more than it does to China.
56% of exports from Sheffield go to the EU, compared to 12% to the US and 2% to China.
Nick Clegg, Liberal Democrat MP for Sheffield Hallam said
"It is not surprising to see that more than half of Sheffield's exports go to our closest neighbours in the EU.
"The government's reckless plans to take Britain out of the Single Market will hit local businesses hard when they are no longer able to export freely to their biggest customer.
"Whether they voted Leave or Remain, no one voted to make our country poorer and to damage local businesses.
"That is why the Liberal Democrats are fighting to give the British public the final say on the Brexit deal. People voted for a departure, so it is only right that they get a say on the destination. "