James Wilby, Molly Renshaw and Joe and Max Litchfield have all been selected to travel to the delayed Olympic Games in Tokyo this summer.
4x100m medley World Champion Wilby, who is from York, was one of four swimmers in the 28-strong squad who was selected earlier this year.
Molly Renshaw, from Mansfield, will be hoping to build on her appearance in the 2016 games final of the 200m breaststroke. A race in which she currently holds the British record.
The Litchfield brothers, who are both from Pontefract, will become only the third set of brothers to represent Britain in the pool at the same Olympics.
Max swam at the 2016 games in the 400m individual medley, finishing fourth.
Joe will be competing in his first Olympics when he swims in the 200m individual medley.
All four swimmers train at the Loughborough National Centre.
Team GB Chef de Mission for Tokyo 2020, Mark England said: "The quality of this team is exceptionally high and the recent selection trials illustrated how dedicated each swimmer has been to earning their selection for Tokyo throughout what has undoubtedly been a very challenging period.
"Congratulations to everyone and we look forward to watching you all in action in Tokyo."