The US musician will perform specially composed song A Life Lived With Grace alongside the London Community Gospel Choir to mark the first day of the Queen’s Platinum Jubilee celebrations.
It will be performed by choirs across all 54 Commonwealth countries.
Grammy-award winning singer Porter said: “I am so excited to be part of this important celebration of the lighting of thousands of beacons across the UK and the Commonwealth.”
More than 2,800 Platinum Jubilee beacons will be lit across the globe, beginning on June 2 with the principal beacon at Buckingham Palace – a 21-metre Tree of Trees sculpture for the Queen’s Green Canopy initiative – which will be illuminated by a senior royal, who is yet to be named.
The first beacons on June 2 – the start of the extended jubilee weekend – are due to be set ablaze thousands of miles away in Tonga and Samoa in the South Pacific, and the final one is in the Central American country of Belize.
A network of flaming tributes will stretch throughout the UK, at historic sites including the Tower of London, Windsor Great Park, Hillsborough Castle, Lambeth Palace and the Queen’s estates at Sandringham and Balmoral.
For the first time, beacons will be lit in all 54 Commonwealth capitals, spanning five continents.
Platinum Beacons: Lighting Up The Jubilee will be broadcast from 8pm on BBC One, presented by Kirsty Young, with Jermaine Jenas based at Buckingham Palace, Gethin Jones in Wales, Carol Kirkwood in Scotland, and Holly Hamilton in Northern Ireland.