John McFall, 41, joined 16 men and women selected for the European Space Agency's (Esa) first new class of astronauts in 13 years.
His right leg was amputated after a motorcycle crash when he was 19. He became a professional athlete and represented Team GB at the Paralympics.
Another British woman, Rosemary Coogan, was selected as a career astronaut.
Esa said it wanted to widen the definition of what it means to have "the right stuff" to go into space.
This announcement does not mean McFall is guaranteed to go into orbit. Instead, he will be part of a feasibility programme to see what the requirements would be for that to be possible.
McFall, who won a bronze medal at the Paralympic Games in 2008 in the T42 200 metres, said he was proud and grateful to have been given the opportunity in "such a brave and bold project".
Speaking to the BBC in Paris, Coogan said "Today is the beginning" and the training will be incredibly exciting, adding that she and her colleagues will "all be in it together".
"I just feel really strongly about all of the things that space can do for us," she said.
It means Samantha Cristoforetti will no longer be Esa's sole female astronaut.
"I am just over-happy that finally we have some some new colleagues," she said. "It's going to be a much more diverse group, and I'm certainly looking forward to not being any more the only woman astronaut in the European astronaut corps. That's important because the current composition of our corps does not reflect where we are in society."
The other Brit on stage in Paris was Meganne Christian, 34. She is an "also suitable" - a reserve and will only get called into the professional corps if there is a vacancy or the UK government were to press for it with extra funding. However, she has joint-UK Australian citizenship, and so there may be a route to space for her through the recently created Australian Space Agency.
The other career astronauts announced in Paris were:
* Marco Sieber, from Switzerland
* Raphaël Liégeois, from Belgium
* Pablo Álvarez Fernández, from Spain
* Sophie Adenot, from France
Their employment with Esa, and their two-year training programme, will start in April next year.
As well as the astronaut showcase on Wednesday, Esa and its member states announced a €16.9bn (£14.7bn; $17.5bn) funding package for space programmes over the next five years.
WATCH: "Potentially, space is for everyone," says Esa para-astronaut John McFall