Ollie Hynd from Kirkby-in-Ashfield goes for gold today in the S8 400m freestyle event.
He won a silver medal in this event at London 2012, but is the current world record holder.
The 21-year old swimmer says he will be "disappointed" if he doesn't bring home gold.
Last year Ollie broke his older brother's world record in the S8 400m freestyle.
Sam Hynd won gold in this event at the Beijing Paralympics, eight years ago but retired from the sport in 2014.
Ollie thanks his brother for getting him involved in swimming and says his brother is responsible for what he has achieved in the pool.
His heat begins at 13:45 and if he qualifies he goes in the final later at 21:45.