The pair will each perform a set at BT London Live's series of concerts in Hyde Park during the London 2012 Olympic Games.
Ferguson will perform in London's Hyde Park on July 31, while Burke will play Hyde Park and Victoria Park on August 2.
Amy Macdonald will play Hyde Park on August 3 and Alyssa Reid will perform in Hyde Park and Victoria Park on August 5.
BT London Live is part of London's biggest free celebration of the London 2012 Olympic Games.
Victoria Park will play host to a 55m high BTObservation Wheel which will allow views of the neighbouring Olympic Park.
Tom Jones, McFly and The Feeling are among the performers previously confirmed for the London-based events.
Meanwhile, Duran Duran, Paolo Nutini, Snow Patrol and Stereophonics will play the opening ceremony gig in Hyde Park, while Blur will play a special set for the closing ceremony on August 12.
Watch the music video for Alexandra Burke's 'Let It Go' below: