The six-figure sponsorship deal kicks off on 2 October and will run for 12 weeks.
The shopping centre will get on-air mentions throughout the promotion and listeners who correctly guess the three celebrities saying ‘Magic 105.4' will win Brent Cross gift cheques.
"We're delighted to welcome Brent Cross on board," said Andria Vidler, managing director Magic.
"This promotion gives everyone the chance to win major cash prizes and the opportunity to go on a truly memorable shopping spree at Brent Cross - and all in time for Christmas."
Tom Nathan, general manager, Brent Cross, said: "Brent Cross is London's most successful shopping centre. As such there is a very good brand fit between Brent Cross and Magic, and with the best-known money game on London radio."