The athletes, comprised of 186 men and 115 women, include seven under-16s as at August 29, the date of the opening ceremony. The youngest is 13-year-old swimmer Chloe Davies, already holder of the British record in the 100m backstroke.
There are also 10 athletes over the age of 50, including 63-year-old archer Kate Kurray who competed in Beijing as well as the 2011 World championships in Turin.
Chef de Mission Craig Hunter said: "I'm proud that we are the first to have registered and look forward to leading this hugely talented team into the Games environment.
"Our first athletes arrive at the Village on Wednesday and we are busy creating the right support set-up for them to go out and produce their lifetime's best at Games-time".
Team GB aim to at least retain their second-place finish in the Paralympic medal table from 2008 where they finished behind hosts China with 102 medals, 42 of them gold.
British Paralympic Association chief executive Tim Hollingsworth hopes not just for an impressive medal haul over the 20 sports, but also that the Games will change perceptions of disabled people.
He said: "Winning medals in front of an excited home crowd will give us a great platform to help shift perceptions of Paralympic sport and ensure that our athletes get the recognition they deserve."
Team numbers by sport:
Five-a-side football : eight
Seven-a-side football: 12
Wheelchair Basketball: 24
Wheelchair fencing: seven
Wheelchair Rugby: 11
Wheelchair Tennis: 10
Athlete partners (cycling pilots, guide runners etc): 13