Thousands are expected to line the streets of London to celebrate the country's Olympic and Paralympic achievements one last time.
Team GB finished third in the medal table with 29 golds, 17 silvers and 19 bronzes while the Paralympic team also finished third with 120 medals, easily surpassing a pre-Games target of 103 medals.
The Greatest Team Parade will see athletes travel on 21 open-top floats, grouped in alphabetical order by their sport.
The stars of the Olympics' "Super Saturday" will be on the first three floats.
The first will include Farah, the Olympic 5,000 and 10,000m winner, followed by heptathlon gold medallist Ennis, with long jump champion Greg Rutherford in the third float.
Team GB's cycling stars Sir Chris Hoy, Jason Kenny, Laura Trott and Victoria Pendleton will be in float seven, followed by double equestrian gold-medal winner Charlotte Dujardin, rowing champion Katherine Grainger, Ben Ainslie, Britain's most successful Olympic sailor, and triathlon gold medallist Alistair Brownlee.
Paralympians Hannah Cockcroft, Jody Cundy, Sophie Christiansen and Jonnie Peacock will be given little time to recover from tonight's closing ceremony to take part in the parade.
British Airways will lead a flypast with the Red Arrows during the event after receiving special permission to fly over The Mall.
The flame-coloured Firefly A319 aircraft, which was used to bring the Olympic Flame to the UK at the start of the Games, will display a special "thank you" message on its underbelly.
During its 20-minute journey, it will pass over the Olympic Park at 3.40pm before reaching The Mall a minute later.
London mayor Boris Johnson said: "This summer our great city has hosted an unbelievable spectacle of sport and thousands will want to celebrate the achievements of our athletes by coming to the parade.
"It promises to be an incredible afternoon but I do want to remind people coming that we expect the route to be extremely busy and planning ahead is absolutely crucial if they are going to be able to make the most of their day.
"Everyone coming should take the time to check on their public transport arrangements and make sure they leave plenty of time to find a good spot.
"But don't forget that there will be continuous television coverage on the main channels that will offer the very best views of the action."
The parade, which has been organised by the mayor in conjunction with the British Olympic Association and the British Paralympic Association, will include more than 90% of Britain's medal winners.
Organisers have warned there will be extensive road closures around the route of the parade, which starts from Mansion House in the City at 1.30pm.
Members of the public will be able to watch the parade as it travels along Queen Victoria Street and Cannon Street, passing St Paul's Cathedral, continuing along Fleet Street, past Aldwych and into The Strand, before reaching Trafalgar Square.
A big screen at the base of Nelson's Column, with live commentary, will allow spectators to cheer on the athletes as the parade makes its way past Trafalgar Square, a Greater London Authority (GLA) spokesman said.
From Trafalgar Square, the athletes will go through Admiralty Arch into The Mall, travelling down to the Queen Victoria Memorial.
Most roads along the route will close at 11am, with those around Guildhall and Gresham Street in the City set to shut at 6am.
An area from Admiralty Arch to the Queen Victoria Memorial will be ticket-only and reserved for groups who had made "an invaluable contribution to the Games and the success of our athletes", the GLA said.
This will include 14,000 volunteers, many from across the ITV Meridian region, members of the blue light services, military personnel, Team GB and ParalympicsGB coaches and support staff, friends and family of the athletes and schoolchildren from every London borough.
See all the pictures from last night's spectacular Paralympic closing ceremony on the ITV News national website here.