The scheme, designed by architect Foster and Partners, was one of 14 academies announced by the government in November. Others will be built in Liverpool, Bristol, Middlesbrough and Manchester.
They are funded by a mixture of public and private money, and are designed to raise standards in underprivileged areas.
The Willesden school, which will specialise in sport, will be partly funded by Frank Lowe of the Octagon Group, a sports marketing firm. Work is due to start as soon as a contractor is chosen. It will be completed in time for the 2003-4 academic year.
The longlist for the scheme had included Gleeson and Willmott Dixon. Last month Willmott Dixon and architect Studio E were picked to develop the Southwark city academy in south London.