Team GB have not entered a team for the event after winning gold in the event at Tokyo 2020.
Team USA will feature two of the athletes that won silver - Kevin McDowell and Taylor Knibb - but is missing Katie Zaferes and Morgan Pearson who were also part of the silver-medal winning team.
France, who were favourites for the gold in Tokyo but took home the bronze, will also compete. Cassandre Beaugrand is the only athlete missing from the line-up while Leonie Periault, Dorian Coninx and Vincent Luis will all compete.
Eight other teams will compete including Australia, New Zealand and Germany.
Getty ImagesCopyright: Getty Images
Olympic silver medallists Team USA - Katie Zaferes, Kevin McDowell, Taylor Knibb and Morgan PearsonImage caption: Olympic silver medallists Team USA - Katie Zaferes, Kevin McDowell, Taylor Knibb and Morgan Pearson
What is the World Triathlon Championship Series?
The World Triathlon Championship Series is a fantastic opportunity to see the very best in the sport, including Olympic, World and European champions compete for the chance to be crowned the best triathlete in the world.
This year’s series began in the Japanese city of Yokohama on 15 May and culminates in the Championship Finals in Edmonton, Canada on 21-22 August.
Each race of the series leading up to the Finals in Edmonton - plus the summer Olympic Games in Tokyo, Japan - award up to 1000 ranking points.
Points from the second half of the year’s re-scheduled Bermuda and Abu Dhabi events will all count towards the 2022 rankings.
The mixed relay final
Getty ImagesCopyright: Getty Images
10 countries go head
to head following a similar format as the Olympic mixed relay competition.
With
teams of four, each athlete will cover a 300m swim, 6.6k bike and 1.9k run
before tagging off to the next teammate, alternating female-male-female-male.
How can I watch the World Triathlon Series in Montreal?
All times are BST and subject to change
BBC iPlayer
You can watch all of the action from the Montreal eliminator of the World Triathlon Championship Series live on BBC iPlayer and the BBC Sport website and app.
All of the action will also be available on catch-up on the BBC iPlayer.
Sunday, 15 August
Mixed relay:19:50 - 21:40 - BBC Red Button, BBC iPlayer and the BBC Sport website and app.
How to get involved with triathlon
BBC Sport
Do you like swimming, cycling and running? If you’ve just answered yes then why don’t you try a triathlon and combine all three sports!
You don’t need to be an Olympic athlete to give it a go, as there’s a variety of distances, age groups and levels of difficulty to choose from.
There are over 750 triathlon clubs in the UK with many of them offering taster sessions for people interested in taking up the sport. You can find a comprehensive list of races viathe British Triathlon event finder.
You can find more information on how to get into triathlons here.
Live Reporting
All times stated are UK
Getty ImagesCopyright: Getty Images Olympic silver medallists Team USA - Katie Zaferes, Kevin McDowell, Taylor Knibb and Morgan PearsonImage caption: Olympic silver medallists Team USA - Katie Zaferes, Kevin McDowell, Taylor Knibb and Morgan Pearson 
Getty ImagesCopyright: Getty Images 
Latest PostWho to look out for
Team GB have not entered a team for the event after winning gold in the event at Tokyo 2020.
Team USA will feature two of the athletes that won silver - Kevin McDowell and Taylor Knibb - but is missing Katie Zaferes and Morgan Pearson who were also part of the silver-medal winning team.
France, who were favourites for the gold in Tokyo but took home the bronze, will also compete. Cassandre Beaugrand is the only athlete missing from the line-up while Leonie Periault, Dorian Coninx and Vincent Luis will all compete.
Eight other teams will compete including Australia, New Zealand and Germany.
What is the World Triathlon Championship Series?
The World Triathlon Championship Series is a fantastic opportunity to see the very best in the sport, including Olympic, World and European champions compete for the chance to be crowned the best triathlete in the world.
This year’s series began in the Japanese city of Yokohama on 15 May and culminates in the Championship Finals in Edmonton, Canada on 21-22 August.
Each race of the series leading up to the Finals in Edmonton - plus the summer Olympic Games in Tokyo, Japan - award up to 1000 ranking points.
Points from the second half of the year’s re-scheduled Bermuda and Abu Dhabi events will all count towards the 2022 rankings.
The mixed relay final
10 countries go head to head following a similar format as the Olympic mixed relay competition.
With teams of four, each athlete will cover a 300m swim, 6.6k bike and 1.9k run before tagging off to the next teammate, alternating female-male-female-male.
How can I watch the World Triathlon Series in Montreal?
All times are BST and subject to change
BBC iPlayer
You can watch all of the action from the Montreal eliminator of the World Triathlon Championship Series live on BBC iPlayer and the BBC Sport website and app.
All of the action will also be available on catch-up on the BBC iPlayer.
Sunday, 15 August
Mixed relay:19:50 - 21:40 - BBC Red Button, BBC iPlayer and the BBC Sport website and app.
How to get involved with triathlon
BBC Sport
Do you like swimming, cycling and running? If you’ve just answered yes then why don’t you try a triathlon and combine all three sports!
You don’t need to be an Olympic athlete to give it a go, as there’s a variety of distances, age groups and levels of difficulty to choose from.
There are over 750 triathlon clubs in the UK with many of them offering taster sessions for people interested in taking up the sport. You can find a comprehensive list of races viathe British Triathlon event finder.
You can find more information on how to get into triathlons here.