Airbus said 50,000 viewed the inaugural flight on the airbus.com Web site.
The new jet, intended to compete with Boeing's 787 Dreamliner and 777 jets, took off at 10 a.m. accompanied by a second plane photographing the flight.
The public viewing took place just a few days before the opening of the largest aviation show in the world, the Paris Air Show, which takes place every two years.
That was no coincidence, The New York Times reported. About 350,000 are expected to attend the show, including an A-list of executives from airlines, supply companies and rival manufacturers.
Airbus is also trying to put a debacle or two behind it. Last year, its parent company, EADS, European Aeronautic Defense & Space, attempted a merger with Britain's BAE Systems, a defense contractor. The idea did not get far off the ground before regulators squashed it.
In addition, the launch of the Airbus super jumbo A380 jet six years ago ran into so many problems the first delivery was three years beyond its original schedule. The delays cost Airbus about $6 billion, the Times said.
Airbus said employees came out in droves to cheer the launch of the A350 XWB over Toulouse and the flight went off without a hitch.
Many of the employees gathered for the flight waved flags that read, "A350 XWB first flight -- We did it!" the company said.