The world's leading disability swimmers are in Montreal for the biggest event since last year's Paralympic Games in London.
Stars including Ellie Simmonds, Jonathan Fox and Ollie Hynd will be in action for the GB team in the first major event for newly appointed national performance director Chris Furber.
The competition, which runs for seven days, will feature more than 500 swimmers from 60 countries
BBC Sport picks out some of the daily highlights of the Championships.
WEDNESDAY 14 AUGUST
Events: S2 50m backstroke, S6 50m freestyle, S5 50m backstroke, S7 50m freestyle, S3 50m freestyle, S8 400m freestyle, SB9 100m breaststroke, S14 100m backstroke, SM12 200m IM, S13 100m butterfly, S11 400m freestyle, 4x50 freestyle relay (20pt), S4 50m butterfly (men)
Brothers Ollie and Sam Hynd won silver and bronze respectively in the S8 400m freestyle in London last year and will be going up against each other again in a battle for the medals.
Sam, the elder at 22, made his Paralympic debut in Beijing, winning gold in the 400 freestyle but in London it was Ollie (18) who shone, winning gold in the 200m IM before his 400m silver and bronze in the backstroke.
Their main challenge in Montreal is set to come from China's Yinan Wang, who won gold in London, while American Ryan Duemler and Dutchman Simon Boer could also test the brothers.
Teenager Chloe Davies will hope to be on the podium in the S14 100m backstroke where Ireland's Bethany Firth and Marlou van der Kulk of the Netherlands will be among her challengers.
There could also be home success in the SB13 100m butterfly where Canada's Valerie Grand'Maison is the favourite for gold.
THURSDAY 15 AUGUST
Events: SM10 200m IM, SB8 breaststroke, S7 100m backstroke, SM5 200m IM, S13 50m freestyle, S3 50m backstroke, S12 50m freestyle, S4 100m freestyle, SM6 200m IM, S11 100m freestyle, 4x100m freestyle relay (34pt), S1 100m freestyle (men)
Jonathan Fox will be bidding to continue his dominance in the S7 backstroke event on Thursday in Montreal.
Fox was Britain's first swimming medallist at the 2012 Paralympics when he triumphed in the backstroke and the defending world champion and world record holder will be hoping to add to his honours.
Ellie Simmonds will be favourite to retain her SM6 200m individual medley title, while Claire Cashmore will hope to beat Russian rival Olesya Vladykina to gold in the SB8 100m breaststroke.
Sascha Kindred goes in the SM6 200m medley, and Hannah Russell and James Clegg are in action in the S12 50m freestyle events.
The first of the relays involving the GB team also takes place with the women's 4x100m freestyle team bidding to reach the podium.
FRIDAY 16 AUGUST
Events: S12 400m freestyle, SB5 100m breaststroke, S2 100m freestyle, S4 200m freestyle, S8 100m butterfly, S13 400m freestyle, S7 100m freestyle, S3 100m freestyle, S11 100m butterfly, S10 100m butterfly, SB14 100m breaststroke, 4x50m medley relay (20pt), S9 400m freestyle (men).
Squad newcomer Stephanie Slater will be hoping to mark her first major international with a medal in the S8 butterfly.
Slater was a talented able-bodied swimmer before suffering nerve damage that left her without the use of her left arm, but she returned to the pool last year and has impressed with her skill and attitude.
The Preston swimmer set a new European record in the event this year but will be challenged by American star Jessica Long and Australian teenager Maddison Elliott.
Josef Craig, the 2012 BBC Young Sports Personality of the Year, will be hoping to win a medal in the S7 100m freestyle along with Jonathan Fox and Matt Walker.
Elsewhere, New Zealand pair Sophie Pascoe and Mary Fisher will be hoping to add to their honours in their respective events.
Pascoe will defend her title in the S10 100m butterfly after setting a world record over 50m earlier this year and Fisher, who is partially sighted, also races in the S11 100m butterfly as the world record holder, having not competed in the event at the London Games.
SATURDAY 17 AUGUST
Events: S6 50m butterfly, SM4 150m IM, SM3 150m IM, S7 50m butterfly, S12 100m backstroke, S8 100m freestyle, S13 100m backstroke, SB11 100m breaststroke, S5 100m freestyle, S10 100m backstroke, S6 100m backstroke, S9 100m butterfly.
Teenager Amy Marren goes for another gold in the 100m butterfly after an impressive build-up to the Worlds.
Marren, who turns 15 out in Montreal, competed at 2012 in the competitive S9 category at the London Paralympics against the likes of South African Natalie du Toit, who retired after the Games.
Marren has taken her chance to shine and could figure on the podium, while team-mate Claire Cashmore will also be aiming for a medal.
Elsewhere, Susie Rodgers and Matt Walker will be hoping for success in their S7 50 butterfly events while Tully Kearney will be aiming for a medal in the S10 100m backstroke.
And Jessica Long, who was born in a Russian orphanage before being adopted by an American family, and who has won 17 Paralympic medals and 17 world titles in her career so far, will bid to make it another in the S8 100m freestyle.
SUNDAY 18 AUGUST
Events: SM7 200m IM, S9 100m backstroke, S6 100m freestyle, S10 50m freestyle, S8 50m freestyle, S5 50m freestyle, S3 50m butterfly, SM14 200m IM, SM11 200m IM, SB12 100m breaststroke, S13 100m freestyle, 4x100m medley relay, SB3 50m breaststroke (men)
Ellie Simmonds will be hoping to finish a busy week on a medal-winning note with a win in the S6 100m freestyle.
Simmonds finished second behind her fellow teenager Victoria Arlen in London and in Arlen's absence will want to show she is still a competitor to be feared.
Chloe Davies and Ben Procter will be hoping for success in the S14 200m individual medley, while Stephanie Millward and Amy Marren could be battling it out for gold in the S9 100m backstroke.
The men's and women's medley relays always provide plenty of excitement with the GB women, who are European champions and won silver in London, hoping to make it one better.
Australian teenager Maddison Elliott will be hoping to back up her S8 50m freestyle world record, which she set earlier this year, with a world title
And as the event comes to a close, Brazil's Andre Brasil will be bidding for victory in the S10 50m freestyle, with interest in Paralympic sport in his home country on the rise as Rio prepares to host the 2016 Paralympics.