The country partnership was secured thanks to trade body TIGA, who will oversee the UK's presence at Gamescom.
Last year, Canada was the official country partner for the European trade show, which was met with disappointment from the UK games industry.
"Britain and Gamescom are an ideal combination," said Gerald Böse, chief executive officer of Koelnmesse, the firm organising Gamescom.
"We are proud to have the European centre of the games industry as a partner country. This sits perfectly within the most important European trade fair."
Gamescom runs from August 17 to August 21 in Germany.
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