The final, which takes place at 19:07 BST, will include Australia’s 2023 world champion and fastest qualifier Sam Short, Northern Ireland’s 800m Olympic champion Daniel Wiffen and defending champion Elijah Winnington, plus James Guy and Jack McMillan, who are medal hopes for England and Northern Ireland respectively.
McCann, who has been part of the Scottish Swimming programme since his teens, will also compete in the 800m and 1500m freestyle events later in the meet.
He finished third in the 800m freestyle and fourth in the 1500m at the British Championships earlier this year.
McCann previously competed at the 2024 Championships, which doubled as Team GB’s Olympic trials.
Speaking after his heat on Saturday, he admitted the Olympics is his ultimate goal.
“The Olympics is always that step even further,” he said.
“Being able to represent Scotland is a good stepping stone on the way to that. Hopefully a couple more years work I will be in the mix for the Olympics.”
His progression to the senior Commonwealth Games comes after representing Scotland at the 2023 Commonwealth Youth Games in Trinidad and Tobago.
There he finished fifth in the 400m freestyle and seventh in the 1,500m freestyle.
He also raced for Great Britain at the 2025 European Open Water Championships in Croatia.