You omitted young Jacob Tremblay. The winner of the 2015 breakthrough artist of the year for "Room". He also won 8 other awards for the same movie. He lived down the road from me here in the Fraser Valley.
Some rather famous people (and a few notable mentions), didn't seem to make your list such as: Christopher Plummer (Sound of Music and acting great), Nathan Fillion (Castle, Firefly), Elliot Page (The Umbrella Academy), Lois Maxwell (Moneypenny in the Connery and Moore Bond films), Nicole de Boer (Cube, Deep Space Nine), Grace Park (Battlestar Galactica), Aaron Ashmore (Killjoys, Warehouse 13), Stephen Amell (Arrow), Yvonne De Carlo (Lily Munster), Rich Little (Impressionist and comedian), William B. Davis (Cigarette Smoking Man in X-Files), Caroline Dhavernas (Wonderfalls), Nia Vardalos (My Big Fat Greek Wedding), Mia Kirshner (Vampire Diaries, Star Trek Discovery), Dan Levy (Schitt's Creek), Sheila McCarthy (A Canadian Treasure), Molly Parker (Lost in Space), Katheryn Winnick (Vikings)... to name just a few. There are dozens more excellent and well-known actors who were born elsewhere and worked in Canada for a long time, becoming Canadian, or were born in Canada and grew up mostly in America, such as King Kong's Fay Wray.
Many of us grow up knowing them so have always known they were Canadian, not Australian, Brits, American, etc. With Australians and Brits it's easier due to the accent. A good half of Americans have very strong accents (US South, Jersey, Midwest, Boston, Minnesota, NYC) so you can tell right away that they're not Canadians. Other Americans sound just like Canadians so it's much harder to tell.
Christopher Plummer as General Chang in Star Trek VI: The Undiscovered Country; William Shatner; John Colicos as Kor in Star Trek TOS and Deep Space 9 and as Count Baltar in Battlestar Galactica (1978), Lorne Greene; Alan Scarfe as Tokath in ST: TNG Birthright were Shakespearean actors at the Stratford Festival in Canada. Nathan Fillion's costar in Castle, Stana Katic is also Canadian Katie Sackhoff as Starbuck and Michael Hogan as Colonel Tigh in Battlestar Galactica (2004) Saul Rubinek in Warehouse 13 Of them all, Michael Hogan's Canadian accent, in my opinion, is strongest. Alan Scarfe's and William B Davis' impeccable diction is a tribute to their classical training. Most were able to hide the pronunciation of 'ou' :) Hmmm... a very SF weighted list! 🇨🇦
Still notably absent: Kevin Durand (3:10 to Yuma, Robin Hood...), Graham Greene (Dances with Wolves, Maverick...) and Tantoo Cardinal (Dances with Wolves, Wind River...), Adam Beach (Windtalkers, Cowboys & Aliens...), Eric Johnson (Vikings, The Knick...), Bruce Greenwood (I, Robot, the Star Trek reboot...), Alison Pill (Scott Pilgrim, Star Trek: Picard...), Jessica Parker Kennedy (Black Sails), not to mention the entire casts of Trailer Park Boys and Letterkenny
