The athletes will travel through central London on six sport-themed floats, before appearing on a stage in front of the National Gallery in Trafalgar Square.
The celebrations in Trafalgar Square will include live interviews and giant video screens showing highlights of the action from Athens.
Four-time gold medal winner Matthew Pinsent said:
"The Parade of the Heroes gives London and the whole of the UK the opportunity to show how supportive the entire nation is of the Olympic and Paralympic movement."
The parade will begin outside the Ritz on Piccadilly at 1.30pm, and will travel along Piccadilly and down Haymarket before arriving in Trafalgar Square.
The parade will be broadcast live on BBC1 between 1.35pm and 2.50pm.