The Airbus A380 is set to make its maiden test flight in April
The twin-deck aircraft can carry about 555 people - more than the Boeing 747 jumbo built by Airbus' main competitor.
The ceremony was attended by European leaders including Tony Blair, Jacques Chirac and Gerhard Schroeder.
French President Jacques Chirac praised the A380 as the "crowning achievement of a human and industrial adventure", describing it as a "European success".
Sign of confidence
It is a symbol of economic strength and technical innovation
Tony Blair
Jumbo versus "superjumbo" The A380 timeline
French, British, German and Spanish leaders represented the Airbus consortium at the "reveal ceremony" in Toulouse.
British Prime Minister Tony Blair praised the "dedication" of all those involved in the project and said the A380 was a symbol of European cooperation at its best.
"This is the most exciting new aircraft in the world, a symbol of economic strength and technical innovation," he said.
"Above all, it is a symbol of confidence that we can compete and win in the global market."
Confident of success
The first test flight of the A380 will take place in April although Airbus is keeping the exact date under wraps.
It will enter service in 2006.
Airbus - a joint venture between European Aeronautic Defence and Space Company (EADS) and BAE Systems - has secured 149 confirmed orders for the A380 from 14 customers, including 11 passenger airlines.
Airlines have taken options on a further 100 planes.
Airbus chief executive Noel Forgeard said he expected sales of the A380 to comfortably exceed 250, the number required for the huge aerospace project to break even.
He said Airbus hoped to sell more than 700 of the aircraft and was in talks about selling the plane to China.
"We'll sell a lot more than 250. We'll sell 700 or 750. You know it is a plane which will fly for 30 or 40 years," he told RTL Radio.
Big is best?
By building the plane - with development costing about $11bn (£6bn) - Airbus is banking on demand for large planes offering cheaper seats between the world's major cities, experts say.
We shall make a family photo; something like this will never happen again
Noel Forgeard, Airbus chief executive
Read more about the Airbus A380 launch ceremony
For consumers, it maps out the future of air travel, or at least the version touted by Airbus.
However, Airbus' main rival Boeing is focusing on smaller new aircraft able to fly direct to a wider number of destinations.
Boeing's rival 7E7 'Dreamliner' project, which will enter service in 2008, has already secured orders from Continental Airlines and Japan Airlines.
Airport changes
The world's busiest airports are having to change their terminal buildings to accommodate the A380.
A380 CUSTOMERS Lufthansa, Virgin Atlantic, Qantas and Malaysian Airlines are among 11 passenger airlines to have agreed to buy the A380. Emirates is its largest customer, ordering 45 while Singapore Airlines will take delivery first in 2006 Airbus' 14 customers, which also include freight and leasing companies, have committed to spend about $40bn on the plane
Heathrow is spending £450m on preparing itself for the arrival of the A380, which will arrive and depart from Terminal 3.
"The A380 is critical for us," Eryl Smith, Heathrow's director of business strategy, planning and development told the Press Association.
"It will change the face of Heathrow and the face of long haul travel."
Controversial subsidies
Without government assistance, the A380 would probably never have been built.
Billions of euros have been handed over in "launch aid loans" in recent years - under generous repayment terms - to assist Airbus's development of the A380.
Airbus has downplayed the cost of the project despite the fact it could run as much as 1.5bn euros over budget.
"That sounds quite a lot of money until you realise you are dealing with a programme which is about 11bn euros," commercial director John Leahy told the BBC.
In a ceremony attended by several European political leaders and 5,000 VIP guests, Airbus unveiled plans for the A380, a twin-deck aircraft that can carry up to 840 people in all-economy class (550 for a Boeing 747), or 555 people in typical three mixed classes layout.

The new aircraft will take the world's-largest title away from rival Boeing's 747. Boeing's upcoming new design, the 7e7, does not attempt to compete directly with the A380 but instead is aimed at a more efficient and comfortable flight at 200-250 seats.

Airbus chief executive Noel Forgeard stated that he expected sales of the aircraft to exceed the 250 required for the project to break even.  To date, 149 confirmed orders for the aircraft have been received.  Airbus has hopes that sales will exceed 700.  The company is currently in talks with China regarding possible sales there.

The first test flight of the aircraft may take place as early as March, and the first commercial flight is expected to take off in mid-2006 from Singapore's Changi Airport.

British and American airline Virgin Atlantic has purchased six of these aeroplanes and intend to fit them with gyms and bars as well as seats.