TV On The Radio and Ghostpoet are also set to play the Big Gig which takes place Friday 1 July.
This new incarnation of Massive Attack will feature a "new and provocative audio-visual live show... designed by Robert Del Naja and longtime visual collaborators United Visual Artists."
Tickets for the Massive Attack-headlined event will be on sale 11 March (7 March presale) priced from £59.50.
Alun Mainwaring, Head of Events at The Royal Parks says of the new announcements: “The line-up for 2016 just keeps on getting better. Having a huge group like Massive Attack kick off this year’s event is a fitting start to what promises to be another unforgettable 10 days of entertainment at Barclaycard presents British Summer Time Hyde Park. The success of this event is so important to us as it raises vital funds which go back into conserving and enhancing this iconic park for all to enjoy.”
Other British Summer Time headliners this year are Florence and The Machine/Kendrick Lamar, Mumford & Sons, and Take That.