Margaret Thatcher died on April 8 of a stroke.
Buckingham Palace said on Tuesday the queen and her husband, Prince Philip, would attend the ceremony at St Paul's Cathedral, which is expected to draw dignitaries from around the world.
The only other prime minister whose funeral the monarch has attended was that of Britain's World War II leader, Winston Churchill, in 1965.
Churchill was the last British leader to receive a state funeral, also at St Paul's.
Thatcher's service, a ceremonial funeral with full military honours, is not officially a state funeral, which requires a vote in Parliament. But the ceremony features the same level of pomp and honour afforded Princess Diana and the Queen Mother Elizabeth.
Thatcher's coffin will lie overnight at the Houses of Parliament ahead of the funeral, before being taken by hearse to the church of St Clement Danes and then, on a horse-drawn gun carriage, to the 17th-century cathedral along a route lined by military personnel.
The televised funeral will be followed by a private cremation.
Early on Tuesday, undertakers removed Thatcher's body from London's Ritz Hotel where she died Monday at the age of 87. A van carrying Thatcher's casket left the hotel for an undisclosed location, where it will remain during preparations for the funeral. – Sapa-AP