Friday's service also falls on the Duke of Edinburgh's 95th birthday.
Rt Revd David Ison, Dean of St Paul's Cathedral, told Premier that the service takes into account how multi-cultural and multi-faith the UK is.
He said: "What we're doing is to invite people in so far as they're able to affirm before God all the things, on behalf of the nation and their own faith communities, their thanks for what Queen Elizabeth has done for all of us, we're doing it all together as one nation before God."
The new Mayor of London, Sadiq Khan and the Prime Minister will be in attendance as well as a host of famous faces including Clare Balding and David Attenborough, who will be conducting a reading.
The prayers have been specially written by the Revd James Milne, Sacrist of St Paul's, and will be led by six people, five of whom represent aspects of the Queen's life and role and one of whom was born on the same day as the Queen.
Who's reading prayers:
- Clare Balding, BBC Commentator, whose family has trained some of the Queen's Horses, represents the sport of horse racing
- Oscar Matthews is a Deputy Sergeant Footman in the Royal Household
- Hilda Price from Cardiff, the widow of an Anglican Priest and a leading light in the Mother's Union, was born on the same day as the Queen - 21 April 1926
- Fitzrene Headley, a young Barrister from Gray's Inn, represents the Law
- Cadet Lance Corporal Tamara Cakmak, of the City of London Academy, Islington, "Honourable Artillery Company" Combined Cadet Force represents the Armed Forces
- Baroness Scotland is Secretary General of the Commonwealth of which the Queen is Head and for which the Queen has a particular affection and regard
The Prime Minister will read the New Testament which speaks of God supplying our needs through the beauty and bounty of creation and encourages us not to worry about the things that God will supply for us but to focus on our faith in God's Kingdom.
Rt Revd David Ison said they chose special poems, music and prayers to suit the Queen.
"All the different parts of the service have some connection to the theme of royalty and particularly to the Queen in term of the composers," he said.
"But also relating to the Queen's own Christian faith, there's a reading in psalm 139 about that sense of being made by God from the womb, about being called to God's service."
The congregation will sing the national anthem as well as hymns at the service.
Listen to Premier's Hannah Tooley speak to Rt Revd David Ison here:
