Liam Heath will look to become the first British athlete to retain an Olympic canoeing title but Joe Clarke has missed out on the squad for Tokyo 2020.
Heath, who claimed world gold in August, won K2 bronze at London 2012 and K1 200m gold at Rio 2016.
Rio 2016 K1 champion Clarke lost out to world number 16 Bradley Forbes-Cryans.
Three-time Olympic medallist David Florence also missed out.
"Being selected for a third Olympics is a huge honour. Each Games is special in its own way. I'm excited to get to Tokyo and I've no doubt it will be amazing," said Heath.
He is among five paddlers to be selected for Tokyo 2020.
The other four - Mallory Franklin (C1), Kimberley Woods (K1), Forbes-Cryans (K1) and Adam Burgess (C1) - are slalom specialists and will make their Olympic debuts.
Clarke & Florence miss out
There are no places for 26-year-old Clarke or 37-year-old Florence.
Clarke finished the 2019 season ranked second in the world, but was edged out of a place at Tokyo 2020 under British Canoeing's first-past-the-post policy after finishing behind Forbes-Cryans at the World Championships.
"It's been an absolute dream of mine to compete at the Olympic Games and to have that opportunity now is incredible," said World Cup silver medallist Forbes-Cryans.
Burgess - Britain's first under-23 world champion in 2015 - won an equally tight dual with Florence for the place in the men's C1 event.
Franklin, who claimed the C1 world title in 2017, and three-time world team champion Woods will be looking to become Britain's first female Olympic medallists in the sport since Helen Reeves claimed bronze at Athens 2004.
"It's absolutely gutting for the ones who haven't made it," said British Canoeing performance director Paul Ratcliffe, who missed out on selection in 2004 after winning Olympic silver in 2000.
"There's only four (slalom) athletes who can go to the Olympic Games and we selected the four that have come through our system and selection policy."
He said Clarke still had "many more medals in him", adding: "He's the reserve boat for the Olympic team, he's got European titles to go for next year, World Cup titles.
"It's about how he bounces back now and, with the character and champion he is, I'm sure he's got the fighting spirit in him."